Texas Instruments | TPS65263-1Q1 4.0- to 18-V Input Voltage, 3-A/2-A/2-A Output Current Triple Synchronous Step-Down Converter With I2C Controlled Dynamic Voltage Scaling | Datasheet | Texas Instruments TPS65263-1Q1 4.0- to 18-V Input Voltage, 3-A/2-A/2-A Output Current Triple Synchronous Step-Down Converter With I2C Controlled Dynamic Voltage Scaling Datasheet

Texas Instruments TPS65263-1Q1 4.0- to 18-V Input Voltage, 3-A/2-A/2-A Output Current Triple Synchronous Step-Down Converter With I2C Controlled Dynamic Voltage Scaling Datasheet
Product
Folder
Order
Now
Technical
Documents
Support &
Community
Tools &
Software
Reference
Design
TPS65263-1Q1
SLVSDY9 – MARCH 2017
TPS65263-1Q1 4.0- to 18-V Input Voltage, 3-A/2-A/2-A Output Current Triple Synchronous
Step-Down Converter With I2C Controlled Dynamic Voltage Scaling
1 Features
3 Description
•
•
The TPS65263-1Q1 incorporates triple-synchronous
buck converters with 4.0- to 18-V wide input voltage.
The converter with constant frequency peak current
mode is designed to simplify its application while
giving designers options to optimize the system
according to targeted applications. The switching
frequency of the converters is adjustable from 200
kHz to 2.3 MHz with an external resistor. 180° out-ofphase operation between buck1 and buck2, buck3
(buck2 and buck3 run in phase) minimizes the input
filter requirements.
1
•
•
•
•
•
•
•
•
•
•
•
•
Qualified for Automotive Applications
AEC-Q100 Qualification With the Following
Results:
– Device Temperature Grade 1: –40°C to 125°C
Operating Junction Temperature Range
– Device HBM ESD Classification Level H2
– Device CDM ESD Classification Level C4B
Operating Input Voltage Range 4.0- to 18-V
Maximum Continuous Output Current 3 A/2 A/2 A
I2C Controlled 7-Bits VID Programmable Output
Voltage from 0.68 to 1.95 V With 10-mV Voltage
Step for Buck2
I2C Controlled VID Voltage Transition Slew Rate
for Buck2
I2C Read Back Power Good Status, Overcurrent
Warning and Die Temperature Warning
I2C Compatible Interface With Standard Mode
(100 kHz) and Fast Mode (400 kHz)
Feedback Reference Voltage 0.6 V ±1%
Adjustable Clock Frequency from 200 kHz to 2.3
MHz
FCC Mode (Default)
External Clock Synchronization
Dedicated Enable and Soft-Start Pins for Each
Buck
Output Voltage Power Good Indicator
Thermal Overloading Protection
Each buck in TPS65263-1Q1 can be I2C controlled
for enabling/disabling output voltage, setting the pulse
skipping mode (PSM) or forced continuous current
(FCC) mode at light load condition and reading the
power-good status, overcurrent warning, and die
temperature warning.
The
TPS65263-1Q1
features
overvoltage,
overcurrent, short-circuit, and overtemperature
protection.
Device Information(1)
PART NUMBER
TPS65263-1Q1
PACKAGE
VQFN (32)
BODY SIZE (NOM)
5.00 mm × 5.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
2 Applications
•
•
•
•
The initial startup voltage of each buck can be set
with external feedback resistors. The output voltage
of buck2 can be dynamically scaled from 0.68 to
1.95 V in 10-mV steps with I2C-controlled 7 bits VID.
The VID voltage transition slew rate is programmable
with 3-bits control through I2C bus to optimize
overshoot/undershoot during VID voltage transition.
Automotive
Car Audio/Video
Home Gateway and Access Point Networks
Surveillance
Efficiency vs Output Load
Application Schematic
100%
Vout1
Vin
PVINx
LX1
90%
VIN
80%
TPS65263-1Q1
FB1
Vout2
DVCC
70%
Vout2
LX2
VOUT2
ROSC
FB2
Vout3
SDA
SCL
LX3
SDA
Efficiency (%)
PGOOD
ENx
SSx
60%
50%
40%
30%
20%
4 VIN Vout = 1.5 V
5 VIN Vout = 1.5 V
10%
SCL
AGND
FB3
PGND
0
0.01
0.1
Output Load (A)
1
2
D022
Copyright © 2017, Texas Instruments Incorporated
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
5
6.1
6.2
6.3
6.4
6.5
6.6
5
5
5
5
6
8
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
7.4 Device Functional Modes........................................ 24
7.5 Register Maps ........................................................ 26
8
Application and Implementation ........................ 29
8.1 Application Information............................................ 29
8.2 Typical Application ................................................. 29
9 Power Supply Recommendations...................... 37
10 Layout................................................................... 37
10.1 Layout Guidelines ................................................. 37
10.2 Layout Example .................................................... 38
11 Device and Documentation Support ................. 39
11.1
11.2
11.3
11.4
11.5
Detailed Description ............................................ 12
7.1 Overview ................................................................. 12
7.2 Functional Block Diagram ....................................... 13
7.3 Feature Description................................................. 13
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
39
39
39
39
39
12 Mechanical, Packaging, and Orderable
Information ........................................................... 39
4 Revision History
2
DATE
REVISION
NOTES
March 2017
*
Initial release.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
5 Pin Configuration and Functions
SS1
COMP1
FB1
ROSC
PGOOD
FB3
COMP3
SS3
RHB Package
32-Pin VQFN
Top View
24
23
22
21
20
19
18
17
BST1 25
16
BST3
LX1 26
15
LX3
PGND1 27
14
PGND3
13
PVIN3
12
PVIN2
V7V 30
11
PGND2
EN1 31
10
LX2
EN2 32
9
BST2
PVIN1 28
Thermal
Pad
4
5
6
7
8
VOUT2
FB2
COMP2
SS2
SDA
3
AGND
2
SCL
1
EN3
VIN 29
There is no electric signal down bonded to thermal pad inside IC. Exposed thermal pad must be soldered to PCB for
optimal thermal performance.
Pin Functions
PIN
NAME
DESCRIPTION
NO.
EN3
1
Enable for buck3. Float to enable. Can use this pin to adjust the input UVLO of buck3 with a resistor divider.
SDA
2
I2C interface data pin; float or connect to GND to disable I2C communication
SCL
3
I2C interface clock pin; float or connect to GND to disable I2C communication
AGND
4
Analog ground common to buck controllers and other analog circuits. It must be routed separately from high-current
power grounds to the (–) terminal of bypass capacitor of input voltage VIN.
VOUT2
5
Buck2 output voltage sense pin
FB2
6
Feedback Kelvin sensing pin for buck2 output voltage. Connect this pin to buck2 resistor divider.
COMP2
7
Error amplifier output and loop compensation pin for buck2. Connect a series resistor and capacitor to compensate the
control loop of buck2 with peak current PWM mode.
SS2
8
Soft-start and tracking input for buck2. An internal 5.2-µA pullup current source is connected to this pin. The soft-start
time can be programmed by connecting a capacitor between this pin and ground.
BST2
9
Boot-strapped supply to the high-side floating gate driver in buck2. Connect a capacitor (recommend 47 nF) from BST2
pin to LX2 pin.
LX2
10
Switching node connection to the inductor and bootstrap capacitor for buck2. The voltage swing at this pin is from a
diode voltage below the ground up to PVIN2 voltage.
PGND2
11
Power ground connection of buck2. Connect PGND2 pin as close as practical to the (–) terminal of VIN2 input ceramic
capacitor.
PVIN2
12
Input power supply for buck2. Connect PVIN2 pin as close as practical to the (+) terminal of an input ceramic capacitor
(suggest 10 µF).
PVIN3
13
Input power supply for buck3. Connect PVIN3 pin as close as practical to the (+) terminal of an input ceramic capacitor
(suggest 10 µF).
PGND3
14
Power ground connection of buck3. Connect PGND3 pin as close as practical to the (–) terminal of VIN3 input ceramic
capacitor.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
3
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
Pin Functions (continued)
PIN
NAME
DESCRIPTION
NO.
LX3
15
Switching node connection to the inductor and bootstrap capacitor for buck3. The voltage swing at this pin is from a
diode voltage below the ground up to PVIN3 voltage.
BST3
16
Boot-strapped supply to the high-side floating gate driver in buck3. Connect a capacitor (recommend 47 nF) from BST3
pin to LX3 pin.
SS3
17
Soft-start and tracking input for buck3. An internal 5.2-µA pullup current source is connected to this pin. The soft-start
time can be programmed by connecting a capacitor between this pin and ground.
COMP3
18
Error amplifier output and loop compensation pin for buck3. Connect a series resistor and capacitor to compensate the
control loop of buck3 with peak current PWM mode.
FB3
19
Feedback Kelvin sensing pin for buck3 output voltage. Connect this pin to buck3 resistor divider.
PGOOD
20
Output voltage supervision pin. When all bucks are in PGOOD monitor’s regulation range, PGOOD is asserted high.
ROSC
21
Clock frequency adjustment pin. Connect a resistor from this pin to ground to adjust the clock frequency. When
connected to an external clock, the internal oscillator synchronizes to the external clock.
FB1
22
Feedback Kelvin sensing pin for buck1 output voltage. Connect this pin to buck1 resistor divider.
COMP1
23
Error amplifier output and loop compensation pin for buck1. Connect a series resistor and capacitor to compensate the
control loop of buck1 with peak current PWM mode.
SS1
24
Soft-start and tracking input for buck1. An internal 5.2-µA pullup current source is connected to this pin. The soft-start
time can be programmed by connecting a capacitor between this pin and ground.
BST1
25
Boot-strapped supply to the high-side floating gate driver in buck1. Connect a capacitor (recommend 47 nF) from BST1
pin to LX1 pin.
LX1
26
Switching node connection to the inductor and bootstrap capacitor for buck1. The voltage swing at this pin is from a
diode voltage below the ground up to PVIN1 voltage.
PGND1
27
Power ground connection of buck1. Connect PGND1 pin as close as practical to the (–) terminal of VIN1 input ceramic
capacitor.
PVIN1
28
Input power supply for buck1. Connect PVIN1 pin as close as practical to the (+) terminal of an input ceramic capacitor
(suggest 10 µF).
VIN
29
Buck controller power supply
V7V
30
Internal LDO for gate driver and internal controller. Connect a 1-µF capacitor from the pin to power ground.
EN1
31
Enable for buck1. Float to enable. Can use this pin to adjust the input UVLO of buck1 with a resistor divider.
EN2
32
Enable for buck2. Float to enable. Can use this pin to adjust the input UVLO of buck2 with a resistor divider.
PAD
—
There is no electric signal down bonded to thermal pad inside IC. Exposed thermal pad must be soldered to PCB for
optimal thermal performance.
4
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature (unless otherwise noted)
(1)
MIN
MAX
UNIT
PVIN1, PVIN2, PVIN3,VIN
–0.3
20
V
LX1, LX2, LX3 (Maximum withstand voltage transient < 20 ns)
–1.0
20
V
BST1, BST2, BST3 referenced to LX1, LX2, LX3 pins respectively
–0.3
7
V
EN1, EN2, EN3, V7V, VOUT2, SCL, SDA, PGOOD
–0.3
7
V
FB1, FB2, FB3, COMP1 , COMP2, COMP3, ROSC, SS1, SS2, SS3
–0.3
3.6
V
AGND, PGND1, PGND2, PGND3
–0.3
0.3
V
TJ
Operating junction temperature
–40
150
°C
Tstg
Storage temperature
–55
150
°C
(1)
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic
discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all -2000 2000 pins
(1)
±2000
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins (2)
±500
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
PVIN1, PVIN2, PVIN3,VIN
TJ
MIN
MAX
4
18
UNIT
V
LX1, LX2, LX3 (Maximum withstand voltage transient <20 ns)
–0.8
18
V
BST1, BST2, BST3 referenced to LX1, LX2, LX3 pins respectively
–0.1
6.8
V
EN1, EN2, EN3, V7V, VOUT1, VOUT2, VOUT3, SCL, SDA
–0.1
6.3
V
FB1, FB2, FB3, COMP1 , COMP2, COMP3, SS1, SS2, SS3
–0.1
3
V
Operating junction temperature
–40
125
°C
6.4 Thermal Information
TPS65263-1Q1
THERMAL METRIC (1)
RHB (VQFN)
UNIT
32 PINS
RθJA
Junction-to-ambient thermal resistance
33.3
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
25.7
°C/W
RθJB
Junction-to-board thermal resistance
7.4
°C/W
ψJT
Junction-to-top characterization parameter
0.3
°C/W
ψJB
Junction-to-board characterization parameter
7.3
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
2.1
°C/W
(1)
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
5
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
6.5 Electrical Characteristics
VIN = 12 V, FSW = 500 kHz, TJ = –40°C to 125°C, typical values are at TJ = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
INPUT SUPPLY VOLTAGE
VIN
Input voltage range
UVLO
4
VIN UVLO
18
V
VIN rising
3.5
3.8
4
V
VIN falling
3.1
3.3
3.5
Hysteresis
IDDSDN
Shutdown supply current
500
EN1 = EN2 = EN3 = 0 V
V
mV
4
9.5
18
µA
IDDQ_NSW
EN1 = EN2 = EN3 = 5 V, FB1 =
FB2 = FB3 = 0.8 V
550
780
1150
µA
IDDQ_NSW1
EN1 = 5 V, EN2 = EN3 = 0 V, FB1
= 0.8 V
180
370
590
µA
IDDQ_NSW2
EN2 = 5 V, EN1 = EN3 = 0 V, FB2
= 0.8V
180
370
590
µA
IDDQ_NSW3
EN3 = 5 V, EN1 = EN2 = 0 V, FB3
= 0.8 V
180
370
590
µA
78
185
260
mA
0.594
0.6
0.606
V
V
Input quiescent current without buck1/2/3 switching
V7V
V7V LDO output voltage
IOCP_V7V
V7V LDO current limit
V7V load current = 0 A
6.3
V
FEEDBACK VOLTAGE REFERENCE
VFB
Feedback voltage
VCOMP = 1.2 V
BUCK1, BUCK2, BUCK3
VENXH
EN1/2/3 high-level input voltage
1.12
1.2
1.26
VENXL
EN1/2/3 low-level input voltage
1.05
1.15
1.21
V
IENX1
EN1/2/3 pullup current
ENx = 1 V
2.5
3.9
5.9
µA
IENX2
EN1/2/3 pullup current
ENx = 1.5 V
5.1
6.9
9.2
µA
IENhys
Hysteresis current
2.6
3
3.3
µA
ISSX
Soft-start charging current
3.9
5.2
6.5
µA
tON_MIN
Minimum on-time
50
75
110
ns
Gm_EA
Error amplifier transconductance
–2 µA < ICOMPX < 2 µA
140
300
450
µs
Gm_PS1/2/3
COMP1/2/3 voltage to inductor current Gm (1)
ILX = 0.5 A
ILIMIT1
Buck1 peak inductor current limit
4.3
5.4
6.5
A
ILIMITSINK1
Buck1 low-side sink current limit
0.7
1.3
1.8
A
ILIMIT2/3
Buck2/buck3 peak inductor current limit
2.55
3.3
3.9
A
ILIMITSINK2/3
Buck2/buck3 low-side sink current limit
0.5
1
1.4
Rdson_HS1
Buck1 high-side switch resistance
VIN = 12 V
105
mΩ
Rdson_LS1
Buck1 low-side switch resistance
VIN = 12 V
65
mΩ
Rdson_HS2
Buck2 high-side switch resistance
VIN = 12 V
140
mΩ
Rdson_LS2
Buck2 low-side switch resistance
VIN = 12 V
90
mΩ
Rdson_HS3
Buck3 high-side switch resistance
VIN = 12 V
140
mΩ
Rdson_LS3
Buck3 low-side switch resistance
VIN = 12 V
90
mΩ
256
cycles
8192
cycles
7.4
A/V
A
HICCUP TIMING
tHiccup_wait
Overcurrent wait time (1)
tHiccup_re
Hiccup time before restart (1)
POWER GOOD
FBx undervoltage falling
FBx undervoltage rising
92.5
95
Vth_PG
Feedback voltage threshold
tDEGLITCH(PG)_F
PGOOD falling edge deglitch time
112
tRDEGLITCH(PG)_R
PGOOD rising edge deglitch time
616
IPG
PGOOD pin leakage
VLOW_PG
PGOOD pin low voltage
(1)
6
FBx overvoltage rising
107.5
FBx overvoltage falling
105
ISINK = 1 mA
%VREF
cycles
cycles
0.1
µA
0.4
V
Lab validation result
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
Electrical Characteristics (continued)
VIN = 12 V, FSW = 500 kHz, TJ = –40°C to 125°C, typical values are at TJ = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
430
500
MAX
UNIT
560
kHz
2300
kHz
OSCILLATOR
FSW
Switching frequency
FSW_range
Switching frequency
ROSC = 88.7 kΩ
TSYNC_w
Clock sync minimum pulse width
FSYNC_HI
Clock sync high threshold
VSYNC_LO
Clock sync low threshold
0.4
FSYNC
Clock sync frequency range
200
200
80
ns
2
V
V
2300
kHz
THERMAL PROTECTION
TTRIP_OTP
THYST_OTP
Temperature rising
Thermal protection trip point (1)
Hysteresis
160
°C
20
°C
I2C INTERFACE
Addr
Address (2)
VIH SDA,SCL
Input high voltage
VIL SDA,SCL
Input low voltage
II
Input current
SDA, SCL, VI = 0.4 to 4.5 V
VOL SDA
SDA output low voltage
SDA open drain, IOL = 4 mA
ƒ(SCL)
Maximum SCL clock frequency (2)
400
kHz
tBUF
Bus free time between a STOP and START
condition (2)
1.3
µs
tHD_STA
Hold time (repeated) START condition (2)
0.6
µs
tSU_STO
Setup time for STOP condition (2)
0.6
µs
tLOW
Low period of the SCL clock (2)
1.3
µs
tHIGH
High period of the SCL clock (2)
0.6
µs
tSU_STA
Setup time for a repeated START condition (2)
0.6
µs
0x60H
2
V
10
µA
0.4
(2)
tSU_DAT
Data setup time
tHD_DAT
Data hold time (2)
tRCL
Rise time of SCL signal (2)
tRCL1
–10
V
0.4
0.1
V
µs
0
0.9
µs
Capacitance of one bus line (pF)
20 + 0.1CB
300
ns
Rise time of SCL signal after a repeated START
condition and after an acknowledge bit (2)
Capacitance of one bus line (pF)
20 + 0.1CB
300
ns
(2)
tFCL
Fall time of SCL signal
Capacitance of one bus line (pF)
20 + 0.1CB
300
ns
tRDA
Rise time of SDA signal (2)
Capacitance of one bus line (pF)
20 + 0.1CB
300
ns
tFDA
Fall time of SDA signal (2)
Capacitance of one bus line (pF)
20 + 0.1CB
300
ns
CB
Capacitance of bus line(SCL and SDA) (2)
400
pF
(2)
Not production tested
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
7
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
6.6 Typical Characteristics
VIN
= 12 V, VOUT1 = 1.5 V, VOUT2 = 1.2 V, VOUT3 = 2.5 V, FSW = 500 kHz (unless otherwise noted)
100%
100%
90%
90%
80%
80%
70%
70%
Efficiency (%)
Efficiency (%)
TA = 25°C,
60%
50%
40%
30%
60%
50%
40%
30%
20%
20%
5 VIN
12 VIN
10%
0
0.01
0.1
Output Load (A)
1
5 VIN
12 VIN
10%
0
0.01
2
0.1
Output Load (A)
D002
Figure 1. BUCK1 Efficiency
1
2
D002
Figure 2. BUCK2 Efficiency
100%
1.515
90%
1.51
5 VIN
12 VIN
80%
1.505
Output Voltage (V)
Efficiency (%)
70%
60%
50%
40%
30%
1.5
1.495
1.49
1.485
20%
1.48
5 VIN
12 VIN
10%
0
0.01
1.475
0.1
Output Load (A)
1
2
0
Figure 3. BUCK3 Efficiency
1.5
2
Output Load (A)
2.5
3
D004
2.525
5 VIN
12 VIN
1.215
5 VIN
12 VIN
2.52
2.515
Output Voltage (V)
1.21
Output Voltage (V)
1
Figure 4. BUCK1, Load Regulation
1.22
1.205
1.2
1.195
2.51
2.505
2.5
1.19
2.495
1.185
2.49
1.18
2.485
0
0.5
1
Output Load (A)
1.5
2
0
D005
Figure 5. BUCK2, Load Regulation
8
0.5
D003
Submit Documentation Feedback
0.5
1
Output Load (A)
1.5
2
D006
Figure 6. BUCK3, Load Regulation
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
Typical Characteristics (continued)
TA = 25°C,
VIN
= 12 V, VOUT1 = 1.5 V, VOUT2 = 1.2 V, VOUT3 = 2.5 V, FSW = 500 kHz (unless otherwise noted)
1.51
1.21
IOUT = 0 A
IOUT = 1 A
IOUT = 3 A
1.505
IOUT = 0 A
IOUT = 1 A
IOUT = 2 A
Output Voltage (V)
Output Voltage (V)
1.205
1.5
1.495
1.49
1.2
1.195
1.485
1.48
1.19
4
6
8
10
12
Input Voltage (V)
14
16
18
4
6
Figure 7. BUCK1, Line Regulation
10
12
Input Voltage (V)
14
16
18
D008
Figure 8. BUCK2, Line Regulation
0.606
2.515
IOUT = 0 A
IOUT = 1 A
IOUT = 2 A
0.604
Voltage Reference (V)
2.51
Output Voltage (V)
8
D007
2.505
2.5
0.602
0.6
0.598
0.596
2.495
4
6
8
10
12
Input Voltage (V)
14
16
18
0.594
-50
Figure 9. BUCK3, Line Regulation
-10
10
30
50
70
Junction Temperature (qC)
90
110
130
D010
Figure 10. Voltage Reference vs Temperature
540
15
Shutdown Quiescent Current (uA)
Oscillator Frequency (KHz)
-30
D009
520
500
480
460
-50
-30
-10
10
30
50
70
Junction Temperature (qC)
90
110
130
13
11
9
7
5
-50
-30
D011
ROSC = 88.7 kΩ
-10
10
30
50
70
90
Junction Temperature (qC)
110
130
D012
VIN = 12 V
Figure 11. Oscillator Frequency vs Temperature
Figure 12. Shutdown Quiescent Current vs Temperature
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
9
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
Typical Characteristics (continued)
VIN
= 12 V, VOUT1 = 1.5 V, VOUT2 = 1.2 V, VOUT3 = 2.5 V, FSW = 500 kHz (unless otherwise noted)
5
8
4.6
7.6
En Pin On Pullup (uA)
En Pin On Pullup (uA)
TA = 25°C,
4.2
3.8
3.4
7.2
6.8
6.4
3
-50
-30
-10
EN = 1 V
10
30
50
70
Junction Temperature (qC)
90
110
6
-50
130
VIN = 12 V
-10
EN = 1.5 V
Figure 13. EN Pin Pullup Current vs Temperature,
EN = 1.0 V
Pin Threshold Falling (V)
1.24
110
130
D014
VIN = 12 V
1.2
1.16
-30
-10
10
30
50
70
Junction Temperature (qC)
90
110
1.19
1.15
1.11
1.07
-50
130
-30
-10
D015
VIN = 12 V
10
30
50
70
Junction Temperature (qC)
90
110
130
D016
VIN = 12 V
Figure 15. EN Pin Threshold Rising vs Temperature
Figure 16. EN Pin Threshold Falling vs Temperature
5.6
5.8
High Side Current Limit (A)
5.4
Soft Start Current (mA)
90
1.23
1.12
-50
5.2
5
4.8
4.6
-50
-30
-10
10
30
50
70
Junction Temperature (qC)
90
110
130
5.6
5.4
5.2
5
-50
-30
D017
VIN = 12 V
-10
10
30
50
70
Junction Temperature (qC)
90
110
130
D018
VIN = 12 V
Figure 17. SS Pin Charge Current vs Temperature
10
10
30
50
70
Junction Temperature (qC)
Figure 14. EN Pin Pullup Current vs Temperature,
EN = 1.5 V
1.28
Pin Threshold Raising (V)
-30
D013
Figure 18. Buck1 High-Side Current Limit vs Temperature
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
Typical Characteristics (continued)
VIN
= 12 V, VOUT1 = 1.5 V, VOUT2 = 1.2 V, VOUT3 = 2.5 V, FSW = 500 kHz (unless otherwise noted)
3.8
3.8
3.6
3.6
High Side Current Limit (A)
High Side Current Limit (A)
TA = 25°C,
3.4
3.2
3
2.8
-50
-30
-10
10
30
50
70
Junction Temperature (qC)
90
110
130
3.4
3.2
3
2.8
-50
-30
D019
VIN = 12 V
-10
10
30
50
70
Junction Temperature (qC)
90
110
130
D020
VIN = 12 V
Figure 19. Buck2 High-Side Current Limit vs Temperature
Figure 20. Buck3 High-Side Current Limit vs Temperature
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
11
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
7 Detailed Description
7.1 Overview
The TPS65263-1Q1 is a monolithic, triple-synchronous step-down (buck) converter with 3-A/2-A/2-A output
currents. A wide 4- to 18-V input supply voltage range encompasses most intermediate bus voltages operating
off 5-, 9-, 12-, or 15-V power bus. The feedback voltage reference for each buck is 0.6 V. Each buck is
independent with dedicated enable, soft-start, and loop compensation pins.
The TPS65263-1Q1 is equipped with an I2C compatible bus for communication with SoC to control buck
converters. Through the I2C interface, SoC can enable or disable the buck converters, set output voltage
(BUCK2 only), and read status registers. External feedback divider resistors can set the initial start-up voltage of
the buck2. After the voltage identification VID DAC is updated via the I2C, output voltage of the buck2 can be
independently programmed with 7 bits VID from 0.68 to 1.95 V in 10-mV voltage step resolution. Output voltage
of the buck2 transition begins after the I2C interface receives the command for the GO bit in the command
register.
If SDA and SCL pins are floated or are connected to GND, the I2C communication will be rejected and the
TPS65263-1Q1 will operate as a traditional triple buck. Each buck on or off is separately controlled by the
relevant enable pin. Buck2’s output voltage is set with the external feedback divider resistors.
In the light load condition, the converter operates at continuous current mode (CCM) with a fixed frequency for
optimized output ripple. PSM can be enabled through I2C so that the converter automatically operates in pulse
skipping mode (PSM) to save power.
The TPS65263-1Q1 implements a constant frequency, peak current mode control that simplifies external loop
compensation. The wide switching frequency of 200 kHz to 2.3 MHz allows for optimizing system efficiency,
filtering size, and bandwidth. The switching frequency can be adjusted with an external resistor connecting
between the ROSC pin and ground. The TPS65263-1Q1 also has an internal phase locked loop (PLL) controlled
by the ROSC pin that can be used to synchronize the switching cycle to the falling edge of an external system
clock. The switching clock of buck1 is 180° out-of-phase operation from the clocks of buck2 and buck3 channels
to reduce input current ripple, input capacitor size, and power-supply-induced noise.
The TPS65263-1Q1 is designed for safe monotonic startup into prebiased loads. The default startup is when VIN
is typically 3.8 V. The ENx pin can also be used to adjust the input voltage undervoltage lockout (UVLO) with an
external resistor divider. In addition, the ENx pin has an internal 3.9-µA current source, so the EN pin can be
floating for automatically powering up the converters.
The TPS65263-1Q1 reduces the external component count by integrating the bootstrap circuit. The bias voltage
for the integrated high-side MOSFET is supplied by a capacitor between the BST and LX pins. A UVLO circuit
monitors the bootstrap capacitor voltage VBST-VLX in each buck. When VBST-VLX voltage drops to the threshold,
LX pin is pulled low to recharge the bootstrap capacitor. The TPS65263-1Q1 can operate at 100% duty cycle as
long as the bootstrap capacitor voltage is higher than the BOOT-LX UVLO threshold, which is typically 2.1 V.
The TPS65263-1Q1 has power-good comparators with hysteresis, which monitor the output voltages through
internal feedback voltages. I2C can read the power-good status with the command register. The device also
features the PGOOD pin to supervise output voltages of the buck converter. When all bucks are in regulation
range and power sequence is done, PGOOD is asserted high.
The SS (soft-start/tracking) pin is used to minimize inrush currents or provide power-supply sequencing during
power up. A small value capacitor or resistor divider is connected to the pin for soft start or voltage tracking.
The TPS65263-1Q1 is protected from overload and overtemperature fault conditions. The converter minimizes
excessive output overvoltage transients by taking advantage of the power-good comparator. When the output is
over, the high-side MOSFET is turned off until the internal feedback voltage is lower than 105% of the 0.6-V
reference voltage. The TPS65263-1Q1 implements both high-side MOSFET overload protection and bidirectional
low-side MOSFET overload protections to avoid inductor current runaway. If the overcurrent condition has lasted
for more than the OC wait time (256 clock cycle), the converter shuts down and restarts after the hiccup time
(8192 clock cycles). The TPS65263-1Q1 shuts down if the junction temperature is higher than thermal shutdown
trip point. When the junction temperature drops 20°C typically below the thermal shutdown trip point, the
TPS65263-1Q1 is restarted under control of the soft-start circuit automatically.
12
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
7.2 Functional Block Diagram
VIN
ROSC
21
VIN
29
CLK1
V7V LDO
Bias
CLK2
30
CLK3
V7V
CLK/SYNC/
Phase Shift
EN1
EN2
EN3
DVCC
en_buck1
ien_buck1
ien_buck2
I2C
Bus
SDA
2
SCL
3
clk
V7V
enable
VIN
ien_buck1
V7V
BST
ien_buck3
BUCK1
I2C
LX
7
COMP
PGND
SS
PVIN1
25
BST1
26
LX1
27
PGND1
24
SS1
22
FB1
23
COMP1
12
PVIN2
9
BST2
VIN
OT warning
vfb1
vfb
28
PGOOD
Over
Temp
en_buck2
clk
V7V
enable
VIN
VIN
vfb1
PGOOD
Power
Good
20
vfb2
BST
ien_buck2
vfb3
BUCK2
LX
COMP
PGND
3.9 uA
EN1
3 uA
en_buck1
6.3 V
PGND2
8
SS2
6
FB2
5
VOUT2
7
COMP2
1.2 V
3.9 uA
I2C Reg.
3 uA
32
7-BIT
I2C Reg.
en_buck2
2K
6.3 V
1.2 V
3.9 uA
EN3
11
MUX
31
2K
EN2
SS
LX2
vfb2
vfb
10
3 uA
1
en_buck3
2K
6.3 V
1.2 V
en_buck3
clk
V7V
enable
VIN
BST
ien_buck3
BUCK3
LX
COMP
SS
13
PVIN3
16
BST3
15
LX3
14
PGND3
17
SS3
19
FB3
18
COMP3
VIN
vfb3
vfb
PGND
V7V
AGND
4
Copyright © 2017, Texas Instruments Incorporated
7.3 Feature Description
7.3.1 Adjusting the Output Voltage
The output voltage of each buck is set with a resistor divider from the output of buck to the FB pin. TI
recommends to use 1% tolerance or better resistors.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
13
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
Feature Description (continued)
Vout
R1
FB
R2
COMP
0.6 V
Figure 21. Voltage Divider Circuit
R2 = R1 ´
0.6
Vout - 0.6
(1)
To improve efficiency at light loads consider using larger value resistors. If the values are too high, the regulator
is more sensitive to noise. Table 1 shows the recommended resistor values.
Table 1. Output Resistor Divider Selection
OUTPUT VOLTAGE
(V)
R1
(kΩ)
R2
(kΩ)
1
10
15
1.2
10
10
1.5
15
10
1.8
20
10
2.5
31.6
10
3.3
45.3
10
3.3
22.6
4.99
5
73.2
10
5
36.5
4.99
The output voltage of the buck converter can be dynamically scaled by I2C-controlled 7-bit register, VOUTx_SEL.
Before I2C communication, the output voltage is set with the resistor divider from the output of buck to the FB
pin. When the GO bit is set to 1 through the I2C interface, the buck converter switches the external resistor
divider to the internal resistor divider as shown in Figure 22. The output voltage can be selected among 128
voltages with voltage identifications (VID) shown in Table 2. The output voltage range of dynamic voltage scaling
is 0.68 to 1.95 V with 10-mV resolution of each voltage step.
Vout2
VOUT2
VOUT_ SEL<0:6>
R1
R1
FB2
7.5 K ~ 207 K
0
COMP2
1
R2
R2
AGND
150 K
0.6 V
VOUT_ SEL<7>
³*2´ %LW
Figure 22. Voltage Divider Circuit
14
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
Table 2. VOUT Output Voltage Setting
OUT_SEL
<7:0>
VOUT
(V)
VOUT_SEL
<7:0>
VOUT
(V)
VOUT_SEL
<7:0>
VOUT
(V)
VOUT_SEL
<7:0>
VOUT
(V)
0
0.68
1
0.69
20
1
40
1.32
60
1.64
21
1.01
41
1.33
61
2
1.65
0.7
22
1.02
42
1.34
62
1.66
3
0.71
23
1.03
43
1.35
63
1.67
4
0.72
24
1.04
44
1.36
64
1.68
5
0.73
25
1.05
45
1.37
65
1.69
6
0.74
26
1.06
46
1.38
66
1.7
7
0.75
27
1.07
47
1.39
67
1.71
8
0.76
28
1.08
48
1.4
68
1.72
9
0.77
29
1.09
49
1.41
69
1.73
A
0.78
2A
1.1
4A
1.42
6A
1.74
B
0.79
2B
1.11
4B
1.43
6B
1.75
C
0.8
2C
1.12
4C
1.44
6C
1.76
D
0.81
2D
1.13
4D
1.45
6D
1.77
E
0.82
2E
1.14
4E
1.46
6E
1.78
F
0.83
2F
1.15
4F
1.47
6F
1.79
10
0.84
30
1.16
50
1.48
70
1.8
11
0.85
31
1.17
51
1.49
71
1.81
12
0.86
32
1.18
52
1.5
72
1.82
13
0.87
33
1.19
53
1.51
73
1.83
14
0.88
34
1.2
54
1.52
74
1.84
15
0.89
35
1.21
55
1.53
75
1.85
16
0.9
36
1.22
56
1.54
76
1.86
17
0.91
37
1.23
57
1.55
77
1.87
18
0.92
38
1.24
58
1.56
78
1.88
19
0.93
39
1.25
59
1.57
79
1.89
1A
0.94
3A
1.26
5A
1.58
7A
1.9
1B
0.95
3B
1.27
5B
1.59
7B
1.91
1C
0.96
3C
1.28
5C
1.6
7C
1.92
1D
0.97
3D
1.29
5D
1.61
7D
1.93
1E
0.98
3E
1.3
5E
1.62
7E
1.94
1F
0.99
3F
1.31
5F
1.63
7F
1.95
7.3.2 Enable and Adjusting UVLO
The ENx pin provides electrical on and off control of the device. After the ENx pin voltage exceeds the threshold
voltage, the device starts operation. If each ENx pin voltage is pulled below the threshold voltage, the regulator
stops switching and enters a low Iq state.
The EN pin has an internal pullup current source, allowing the user to float the EN pin for enabling the device. If
an application requires controlling the EN pin, use open-drain or open-collector output logic to interface with the
pin.
The device implements internal UVLO circuitry on the VIN pin. The device is disabled when the VIN pin voltage
falls below the internal VIN UVLO threshold. The internal VIN UVLO threshold has a hysteresis of 500 mV. If an
application requires either a higher UVLO threshold on the VIN pin or a secondary UVLO on the PVINx in split
rail applications, then the user can configure the ENx pin as shown in Figure 23, Figure 24, and Figure 25. When
using the external UVLO function, TI recommends to set the hysteresis >500 mV.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
15
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
The EN pin has a small pullup current, Ip, which sets the default state of the pin to enable when no external
components are connected. The pullup current is also used to control the voltage hysteresis for the UVLO
function because it increases by Ih after the EN pin crosses the enable threshold. The UVLO thresholds can be
calculated using Equation 2 and Equation 3.
R1
æV
ö
VSTART ç ENFALLING ÷ - VSTOP
è VENRISING ø
=
æ
ö
V
IP ç 1 - ENFALLING ÷ + Ih
VENRISING ø
è
R2 =
(2)
R1 ´ VENFALLING
(
VSTOP - VENFALLING + R1 Ih + Ip
)
where
•
•
•
•
Ih = 3 µA
Ip = 3.9 µA
VENRISING = 1.2 V
VENFALLING = 1.15 V
(3)
VIN
PVIN
i
i
h
h
R1
R1
i
i
p
EN
p
EN
R2
R2
Figure 23. Adjustable VIN UVLO
Figure 24. Adjustable PVIN UVLO, VIN > 4 V
PVIN
VIN
i
h
R1
i
p
EN
R2
Figure 25. Adjustable VIN and PVIN UVLO
16
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
7.3.3 Soft-Start Time
The voltage on the respective SS pin controls the startup of buck output. When the voltage on the SS pin is less
than the internal 0.6-V reference, The TPS65263-1Q1 regulates the internal feedback voltage to the voltage on
the SS pin instead of 0.6 V. The SS pin can be used to program an external soft-start function or to allow output
of buck to track another supply during start-up. The device has an internal pullup current source of 5.2 µA
(typical) that charges an external soft-start capacitor to provide a linear ramping voltage at the SS pin. The
TPS65263-1Q1 regulates the internal feedback voltage to the voltage on the SS pin, allowing VOUT to rise
smoothly from 0 V to its regulated voltage without inrush current. The soft-start time can be calculated
approximately by Equation 4.
Css(nF) ´ Vref( V)
Tss(ms) =
Iss(mA )
(4)
Many of the common power-supply sequencing methods can be implemented using the SSx and ENx pins.
Figure 26 shows the method implementing ratiometric sequencing by connecting the SSx pins of three buck
channels together. The regulator outputs ramp up and reach regulation at the same time. When calculating the
soft-start time, the pullup current source must be tripled in Equation 4.
EN
31
EN threshold = 1.2 V
EN1
32
EN2
1
EN3
Vout3 = 2.5 V
24
SS1
Vout1 1.5 V
8
SS2
Vout2 1.2 V
17
SS3
Css
t SS =
CSS × 0.6 V
15.6 µA
Figure 26. Ratiometric Power-Up Using SSx Pins
The user can implement simultaneous power-supply sequencing by connecting the capacitor to the SSx pin,
shown in Figure 27. Using Equation 4 and Equation 5, the capacitors can be calculated.
Css1
Css2
Css3
=
=
Vout1 Vout2 Vout3
(5)
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
17
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
EN
31
EN1
EN threshold = 1.2 V
32
EN2
1
EN3
Vout3 = 2.5 V
24
SS1
Css1
Vout1 1.5 V
8
SS2
Css2
Vout2 1.2 V
17
SS3
Css3
t SS =
CSS 3 × 0.6 V
5.2 µA
Figure 27. Simultaneous Startup Sequence Using SSx Pins
7.3.4 Power-Up Sequencing
The TPS65263-1Q1 has a dedicated enable pin and soft-start pin for each converter. The converter enable pins
are biased by a current source that allows for easy sequencing by the addition of an external capacitor. Disabling
the converter with an active pulldown transistor on the ENx pin allows for predictable power-down timing
operation. Figure 28 shows the timing diagram of a typical buck power-up sequence with connecting a capacitor
at the ENx pin.
A typical 1.4-µA current is charging the ENx pin from input supply. When the ENx pin voltage rises to typical 0.4
V, the internal V7V LDO turns on. A 3.9-µA pullup current is sourcing ENx. After the ENx pin voltage reaches the
ENx enabling threshold, a 3.0-µA hysteresis current sources to the pin to improve noise sensitivity. The internal
soft-start comparator compares the SS pin voltage to 1.2 V. When the SS pin voltage ramps up to 1.2 V,
PGOOD monitor is enabled. After PGOOD deglitch time, PGOOD is deasserted. The SS pin voltage is eventually
clamped around 2.1 V.
18
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
VIN
V7V
EN Threshold
ENx Rise Time
Dictated by CEN
1.2 V
EN
Threshold
Charge CEN
with 6.9 µA
t = CSS × 0.6 V/5.2 µA
ENx
Soft Start Rise Time
Dictated by CSS
0.4 V
About 2.1 V
1.2 V
0.6 V
SSx
Pre-Bias Startup
VOUTx
PGOOD Deglitch Time
t = CENx × (1.2 ± 0.4) V/3.9 µA
t = CSS × 1.2 V/5.2 µA
t = CENx × 0.4 V/1.4 µA
PGOOD
Figure 28. Startup Power Sequence
7.3.5 V7V Low-Dropout Regulator and Bootstrap
Power for the high-side and low-side MOSFET drivers and most other internal circuitry is derived from the V7V
pin. The internal built-in low-dropout linear regulator (LDO) supplies 6.3 V (typical) from VIN to V7V. The user
should connect a 1-µF ceramic capacitor from V7V pin to power ground.
If the input voltage, VIN, decreases to the UVLO threshold voltage, the UVLO comparator detects the V7V pin
voltage and forces the converter off.
Each high-side MOSFET driver is biased from the floating bootstrap capacitor, CB, shown in Figure 29, which is
normally recharged during each cycle through an internal low-side MOSFET or the body diode of a low-side
MOSFET when the high-side MOSFET turns off. The boot capacitor is charged when the BST pin voltage is less
than VIN and BST-LX voltage is below regulation. TI recommends a 47-nF ceramic capacitor. TI recommends a
ceramic capacitor with an X7R or X5R grade dielectric with a voltage rating of 10 V or higher because of the
stable characteristics over temperature and voltage. Each low-side MOSFET driver is powered from the V7V pin
directly.
To improve dropout, the device is designed to operate at 100% duty cycle as long as the BST to LX pin voltage
is greater than the BST-LX UVLO threshold, which is typically 2.1 V. When the voltage between BST and LX
drops below the BST-LX UVLO threshold, the high-side MOSFET is turned off and the low-side MOSFET is
turned on allowing the boot capacitor to be recharged.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
19
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
VIN
PVINx
LDO
+
(VBSTx-VLXx)
±
+2.1 V
nBootUV
V7V
Cbias
1 uF
BSTx
UVLO
Bias
Buck Controller
High-side
MOSFET
nBootUV
CB
Gate Driver
PWM
LXx
Low-side
MOSFET
nBootUV
BootUV
Protection
PWM
Gate Driver
Clk
Figure 29. V7V Linear Dropout Regulator and Bootstrap Voltage Diagram
7.3.6 Out-of-Phase Operation
To reduce input ripple current, the switch clock of buck1 is 180° out-of-phase from the clock of buck2 and buck3.
This enables the system having less input current ripple to reduce input capacitors’ size, cost, and EMI.
20
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
7.3.7 Output Overvoltage Protection (OVP)
The device incorporates an OVP circuit to minimize output voltage overshoot. When the output is overloaded, the
error amplifier compares the actual output voltage to the internal reference voltage. If the FB pin voltage is lower
than the internal reference voltage for a considerable time, the output of the error amplifier demands maximum
output current. After the condition is removed, the regulator output rises and the error amplifier output transitions
to the steady-state voltage. In some applications with small output capacitance, the load can respond faster than
the error amplifier. This leads to the possibility of an output overshoot. Each buck compares the FB pin voltage to
the OVP threshold. If the FB pin voltage is greater than the OVP threshold, the high-side MOSFET is turned off
preventing current from flowing to the output and minimizing output overshoot. When the FB voltage drops lower
than the OVP threshold, the high-side MOSFET turns on at the next clock cycle.
7.3.8 PSM
The TPS65263-1Q1 can enter high-efficiency PSM operation at light load current. To enable PSM operation, set
the VOUTx_COM registers’ bit 1 to '1' through I2C interface.
When a controller is enabled for PSM operation, the peak inductor current is sensed and compared with 310-mA
current typically. Because the integrated current comparator catches the peak inductor current only, the average
load current entering PSM varies with the applications and external output filters. In PSM, the sensed peak
inductor current is clamped at 310 mA, shown in Figure 30.
When a controller operates in PSM, the inductor current is not allowed to reverse. The reverse current
comparator turns off the low-side MOSFET when the inductor current reaches 0, preventing it from reversing and
going negative.
Due to the delay in the circuit and current comparator, tdly (typical 50 nS at Vin = 12 V), the real peak inductor
current threshold to turn off high-side power MOSFET could shift higher depending on inductor inductance and
input/output voltages. Calculate the threshold of peak inductor current to turn off high-side power MOSFET with
Equation 6.
Vin - Vout
´ tdly
ILPEAK = 310 mA +
(6)
L
After the charge accumulated on the Vout capacitor is more than loading need, the COMP pin voltage drops to a
low voltage driven by the error amplifier. There is an internal comparator at COMP pin. If the comp voltage is
<0.35 V, the power stage stops switching to save power.
310 mA
Turn off
high-side power MOSFET
+
ILPEAK
Inductor Peak Current
Inductor
Current Peak
Current
Sensing
x1
±
Current Comparator
Delay: tdly
Figure 30. PSM Current Comparator
7.3.9 Slope Compensation
To prevent the subharmonic oscillations when the device operates at duty cycles greater than 50%, the
TPS65263-1Q1 adds built-in slope compensation, which is a compensating ramp to the switch current signal.
7.3.10 Overcurrent Protection
The device is protected from overcurrent conditions by cycle-by-cycle current limiting on both the high-side
MOSFET and low-side MOSFET.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
21
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
7.3.10.1 High-Side MOSFET Overcurrent Protection
The device implements current mode control that uses the COMP pin voltage to control the turn off of the highside MOSFET and the turn on of the low-side MOSFET on a cycle-by-cycle basis. Each cycle the switch current
and the current reference generated by the COMP pin voltage are compared, when the peak switch current
intersects the current reference, the high-side switch is turned off.
7.3.10.2 Low-Side MOSFET Overcurrent Protection
While the low-side MOSFET is turned on, its conduction current is monitored by the internal circuitry. During
normal operation, the low-side MOSFET sources current to the load. At the end of every clock cycle, the low-side
MOSFET sourcing current is compared to the internally set low-side sourcing current limit. If the low-side
sourcing current is exceeded, the high-side MOSFET is not turned on and the low-side MOSFET stays on for the
next cycle. The high-side MOSFET is turned on again when the low-side current is below the low-side sourcing
current limit at the start of a cycle.
The low-side MOSFET may also sink current from the load. If the low-side sinking current limit is exceeded, the
low-side MOSFET is turned off immediately for the rest of that clock cycle. In this scenario both MOSFETs are
off until the start of the next cycle.
Furthermore, if an output overload condition (as measured by the COMP pin voltage) has lasted for more than
the hiccup wait time which is programmed for 256 switching cycles shown in Figure 31, the device shuts down
and restarts after the hiccup time of 8192 cycles. The hiccup mode helps to reduce the device power dissipation
under severe overcurrent condition.
OCP peak inductor current threshold
OC limiting (waiting) time
256 cycles
hiccup time
8192 cycles
soft start time
t = Css × 0.6 V/5.2 µA
Output over loading
iL
Inductor Current
Soft-start is reset after OC waiting time
About 2.1 V
SS
OC fault removed, soft-start, and output recovery
0.6 V
SS Pin Voltage
Output hard short circuit
Vout
Output Voltage
Figure 31. Overcurrent Protection
7.3.11 Power Good
The PGOOD pin is an open-drain output. When feedback voltage of each buck is between 95% (rising) and
105% (falling) of the internal voltage reference, the PGOOD pin pulldown is deasserted and the pin floats. TI
recommends to use a pullup resistor between the values of 10 and 100 kΩ to a voltage source that is 5.5 V or
less. The PGOOD is in a defined state when the VIN input voltage is greater than 1 V, but with reduced current
sinking capability. The PGOOD achieves full current sinking capability after the VIN input voltage is above UVLO
threshold, which is 3.8 V.
22
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
The PGOOD pin is pulled low when any feedback voltage of buck is lower than 92.5% (falling) or greater than
107.5% (rising) of the nominal internal reference voltage. Also, when the PGOOD is pulled low, if the input
voltage is undervoltage locked up, thermal shutdown is asserted, the EN pin is pulled low or the converter is in
soft-start period.
The power-good indicator for each buck channel can be read back through I2C. The bits in SYS_STATUS[2:0]
(address 0x06H) present the feedback voltage in regulation (logic 1) or not (logic 0) for buck1, buck2, and buck3
respectively
7.3.11.1 Adjustable Switching Frequency
The ROSC pin can be used to set the switching frequency by connecting a resistor to GND. The switching
frequency of the device is adjustable from 200 kHz to 2.3 MHz.
To determine the ROSC resistance for a given switching frequency, use Equation 7 or the curve in Figure 32. To
reduce the solution size, the user should set the switching frequency as high as possible, but consider tradeoffs
of the supply efficiency and minimum controllable on-time.
ƒosc (kHz ) = 37254 ´ R(KW)-0.966
(7)
2300
Switching Frequency (kHz)
2000
1700
1400
1100
800
500
200
10
30
50
70
90
110 130 150 170 190 210 230
ROSC (k:)
D022
Figure 32. ROSC vs Switching Frequency
When an external clock applies to ROSC pin, the internal PLL has been implemented to allow internal clock
synchronizing to an external clock between 200 and 2300 kHz. To implement the clock synchronization feature,
connect a square wave clock signal to the ROSC pin with a duty cycle between 20% to 80%. The clock signal
amplitude must transition lower than 0.4 V and higher than 2.0 V. The start of the switching cycle is synchronized
to the falling edge of ROSC pin.
In applications where both resistor mode and synchronization mode are needed, the user can configure the
device as shown in Figure 33. Before an external clock is present, the device works in resistor mode and ROSC
resistor sets the switching frequency. When an external clock is present, the synchronization mode overrides the
resistor mode. The first time the ROSC pin is pulled above the ROSC high threshold (2.0 V), the device switches
from the resistor mode to the synchronization mode and the ROSC pin becomes high impedance as the PLL
starts to lock onto the frequency of the external clock. TI does not recommend to switch from the synchronization
mode back to the resistor mode because the internal switching frequency drops to 100 kHz first before returning
to the switching frequency set by ROSC resistor.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
23
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
Mode
Selection
IC
ROSC
ROSC
Figure 33. Works With Resistor Mode and Synchronization Mode
7.3.12 Thermal Shutdown
The internal thermal shutdown circuitry forces the device to stop switching if the junction temperature exceeds
160°C typically. The device reinitiates the power-up sequence when the junction temperature drops below 140°C
typically.
7.4 Device Functional Modes
7.4.1 Serial Interface Description
I2C is a 2-wire serial interface developed by NXP Semiconductor (see I2C-Bus Specification, Version 2.1,
January 2000). The bus consists of a data line (SDA) and a clock line (SCL) with pullup structures. When the bus
is idle, both SDA and SCL lines are pulled high. All the I2C-compatible devices connect to the I2C bus through
open-drain I/O pins, SDA and SCL. A master device, usually a microcontroller or a digital signal processor,
controls the bus. The master is responsible for generating the SCL signal and device addresses. The master also
generates specific conditions that indicate the START and STOP of data transfer. A slave device receives and/or
transmits data on the bus under control of the master device.
The TPS65263-1Q1 device works as a slave and supports the following data transfer modes, as defined in the
I2C-Bus Specification: standard mode (100 kbps) and fast mode (400 kbps). The interface adds flexibility to the
power-supply solution, enabling most functions to be programmed to new values depending on the instantaneous
application requirements. Register contents remain intact as long as supply voltage remains above 3.8 V
(typical).
The data transfer protocol for standard and fast modes is exactly the same. Therefore, they are referred to as
F/S-mode in this document. The TPS65263-1Q1 device supports 7-bit addressing. 10-bit addressing and general
call address are not supported.
SDA
tSU,DAT
tLOW
tBUF
tSU,STA
tHD,DAT
tHD,STA
tSU,STO
SCL
tHD,STA
START
CONDITION
tSP
tHIGH
tr
tf
REPEATED START
CONDITION
STOP
CONDITION
START
CONDITION
Figure 34. I2C Interface Timing Diagram
24
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
Device Functional Modes (continued)
7.4.2 I2C Update Sequence
The TPS65263-1Q1 requires a start condition, a valid I2C address, a register address byte, and a data byte for a
single update. After the receipt of each byte, TPS65263-1Q1 device acknowledges by pulling the SDA line low
during the high period of a single clock pulse. A valid I2C address selects the TPS65263-1Q1. TPS65263-1Q1
performs an update on the falling edge of the LSB byte.
When the TPS65263-1Q1 is in hardware shutdown (EN1, EN2, and EN3 pin tied to ground) the device cannot be
updated through the I2C interface. Conversely, the I2C interface is fully functional during software shutdown
(EN1, EN2, and EN3 bit = 0).
S
0 A
7-Bit Slave Address
A
Register Address
A P
Data Byte
Figure 35. I2C Write Data Format
S
7-Bit Slave Address
0
Data Byte
Register1 Address
A
N
A Sr
7-Bit Slave Address
1
A
P
A: Acknowledge
N: Not Acknowledge
S: Start
P: Stop
Sr: Repeated Start
System Host
Chip
Figure 36. I2C Read Data Format
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
25
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
7.5 Register Maps
Table 3. Register Addresses
NAME
BITS
ADDRESS
VOUT2_SEL
8
0x01H
VOUT1_COM
8
0X03H
VOUT2_COM
8
0x04H
VOUT3_COM
8
0X05H
SYS_STATUS
8
0x06H
7.5.1 VOUT2_SEL: Vout2 Voltage Selection Register (Address = 0x01H)
Figure 37. VOUT2_SEL: Vout2 Voltage Selection Register
7
Vout2_Bit7
6
Vout2_Bit6
5
Vout2_Bit5
4
Vout2_Bit4
3
Vout2_Bit3
2
Vout2_Bit2
1
Vout2_Bit1
0
Vout2_Bit0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 4. VOUT2_SEL: Vout2 Voltage Selection Register Field Descriptions
Bit
Field
Type
Reset
Description
7
Vout2_Bit7
R/W
0
“Go” bit, must set 1 to enable I2C controlled VID voltages
6
Vout2_Bit6
R/W
0
5
Vout2_Bit5
R/W
0
4
Vout2_Bit4
R/W
0
128 voltage selections with 7-bits control
Voltage range: 0.68 to 1.95 V
Voltage step resolution: 10 mV
3
Vout2_Bit3
R/W
0
2
Vout2_Bit2
R/W
0
1
Vout2_Bit1
R/W
0
0
Vout2_Bit0
R/W
0
0x00H: Vout2 = 0.68 V;
0x7FH: Vout2 = 1.95 V
7.5.2 VOUT1_COM: Buck1 Command Register (offset = 0x03H)
Figure 38. VOUT1_COM: Buck1 Command Register
7
6
5
4
3
2
N/A
1
Mode1
0
nEN1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 5. VOUT1_COM: Buck1 Command Register Field Descriptions
26
Bit
Field
Type
Reset
Description
7:2
N/A
R/W
000000
Not used
1
Mode1
R/W
0
0: Enable buck 1 PWM operation at light load;
1: Forced buck 1 PSM mode operation
0
nEN1
R/W
0
0: Enable buck1;
1: Disable buck1
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
7.5.3 VOUT2_COM: Buck2 Command Register (offset = 0x04H)
Figure 39. VOUT2_COM: Buck2 Command Register
7
N/A
6
SR3
5
SR2
4
SR1
3
N/A
2
N/A
1
Mode2
0
nEN2
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 6. VOUT2_COM: Buck2 Command Register Field Descriptions
Bit
Field
Type
Reset
Description
7
N/A
R/W
0
Not used
6
SR3
R/W
0
Vout2 VID voltage transition Slew Rate control.
5
SR2
R/W
0
4
SR1
R/W
0
000:
010:
100:
110:
3
N/A
R/W
0
Not used
2
N/A
R/W
0
Not used
1
Mode2
R/W
0
0: Enable buck 2 PWM operation at light load;
1: Forced buck 2 PSM mode operation
0
nEN2
R/W
0
0: Enable buck2;
1: Disable buck2
10
10
10
10
mV/cycle;
mV/4 cycles;
mV/16 cycles;
mV/64 cycles;
001:
011:
101:
111:
10
10
10
10
mV/2 cycles;
mV/8 cycles;
mV/32 cycles;
mV/128 cycles
7.5.4 VOUT3_COM: Buck3 Command Register (offset = 0x05H)
Figure 40. VOUT3_COM: Buck3 Command Register
7
6
5
4
3
2
1
Mode3
N/A
0
nEN3
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 7. VOUT3_COM: Buck3 Command Register Field Descriptions
Bit
Field
Type
Reset
Description
7:2
N/A
R/W
000000
Not used
1
Mode3
R/W
0
0: Enable buck 3 PWM operation at light load;
1: Forced buck 3 PSM mode operation
0
nEN3
R/W
0
0: Enable buck3;
1: Disable buck3
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
27
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
7.5.5 SYS_STATUS: System Status Register (offset = 0x06H)
Figure 41. SYS_STATUS: System Status Register
7
OTP
6
OC3
5
OC2
4
OC1
3
OTW
2
PGOOD3
1
PGOOD2
0
PGOOD1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 8. SYS_STATUS: System Status Register Field Descriptions
Bit
Field
Type
Reset
7
OTP
R
0
6
OC3
R
0
5
OC2
R
0
Description
1: Die temperature over 160°C, which triggers over temperature protection;
0: Die overtemperature protection is not triggered.
1: Buck3 over current limiting and hiccup protection is triggered;
0: Buck3 current not beyond the current limit.
1: Buck2 overcurrent limiting and hiccup protection is triggered;
0: Buck2 current not beyond the current limit.
4
OC1
R
0
3
OTW
R
0
1: Buck1 overcurrent limiting and hiccup protection is triggered;
0: Buck1 current not beyond the current limit.
1: Die temperature over 125°C;
0: Die temperature below 125°C.
2
PGOOD3
R
0
1
PGOOD2
R
0
0
PGOOD1
R
0
1: Vout3 in power good monitor’s range;
0: Vout3 not in power good monitor’s range.
1: Vout2 in power good monitor’s range;
0: Vout2 not in power good monitor’s range.
1: Vout1 in power good monitor’s range ;
0: Vout1 not in power good monitor’s range.
28
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
8 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The device is triple-synchronous step-down dc/dc converter with I2C interface. It is typically used to convert a
higher dc voltage to lower dc voltages with continuous available output current of 3 A/2 A/2 A.
8.2 Typical Application
The following design procedure can be used to select component values for the TPS65263-1Q1. This section
presents a simplified discussion of the design process.
VIN 4 to 18 V
VIN
R1
C5
10 µF
C6
10 µF
C4
1 µF
C7
10 µF
U?
29
28
12
13
GND
VIN
PVIN1
PVIN2
PVIN3
BST1
LX1
GND
V7V
C9
1 µF
C11
GND 22 pF
30
23
R8
10.0 kΩ
C14
7
R10
10.0 kΩ
C15 22pF
2200 pF
18
R12
10.0 kΩ
C16
C18 22 pF
3300 pF
C19
3300 pF
GND
FB1
BST2
COMP2
LX2
31
32
1
EN1
EN2
EN3
FB2
BST3
GND
24
8
17
GND
SS1
SS2
SS3
LX3
C22
0.01 µF
C25
0.01 µF
2
3
GND
GND
SDA
PGOOD
SDA
SCL
ROSC
PAD
GND
4
SCL
VOUT1
VFB1
R7
9
C10
0.047 µF
GND
PGND1
PGND2
PGND3
AGND
15.0 kΩ
C8
VFB1
R5
10.0 kΩ
GND
82 pF
GND
VOUT2 1.2 V 2 A
VOUT2
C12
22 µF
C13
22 µF
R14
10.0 kΩ
C17
VFB2
R15
16
C20
0.047 µF
GND
VFB2
(VOUT2 0.68 to 1.95 V via I2C)
R13
10.0 kΩ
GND
100pF
L3
GND
0
15
19
R6
L2
5
6
C3
22 µF
0
10
VOUT3 2.5 V 2 A
VOUT3
C23
22 µF
4.7 µH
FB3
C21
0.01 µF
22
VOUT1 1.5 V 3 A
C2
22 µF
4.7 µH
26
4.7 µH
COMP3
VOUT2
EN1
EN2
EN3
L1
0
25
V7V
COMP1
C1
0.047 µF
VFB3
R30
20
21
27
11
14
R23
V7V
GND
C24
22 µF
R22
31.6 kΩ
C26
VFB3
R21
10.0 kΩ
GND
22 pF
100 kΩ
GND
88.7 kΩ
GND
TPS65263-1Q
GND
GND
Copyright © 2017, Texas Instruments Incorporated
Figure 42. Typical Application Schematic
8.2.1 Design Requirements
This example details the design of triple-synchronous step-down converter. A few parameters must be known to
start the design process. These parameters are typically determined at the system level. For this example, we
start with the following known parameters:
Table 9. Design Parameters
PARAMETER
VALUE
Vout1
1.5 V
Iout1
3A
Vout2
1.2 V
Iout2
2A
Vout3
2.5 V
Iout3
2A
Transient response 1-A load step
±5%
Input voltage
12 V normal, 4 to 18 V
Output voltage ripple
±1%
Switching frequency
500 kHz
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
29
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
8.2.2 Detailed Design Procedure
8.2.2.1 Output Inductor Selection
To calculate the value of the output inductor, use Equation 8. LIR is a coefficient that represents the amount of
inductor ripple current relative to the maximum output current. The inductor ripple current is filtered by the output
capacitor. Therefore, choosing high inductor ripple currents impact the selection of the output capacitor because
the output capacitor must have a ripple current rating equal to or greater than the inductor ripple current. In
general, the inductor ripple value is at the discretion of the designer; however, LIR is normally from 0.1 to 0.3 for
the majority of applications.
V
Vout
- Vout
L = inmax
´
Io ´ LIR
Vinmax ´ ƒ sw
(8)
For the output filter inductor, it is important that the RMS current and saturation current ratings not be exceeded.
Calculate the RMS and peak inductor current from Equation 10 and Equation 11.
V
Vout
- Vout
Iripple = inmax
´
L
Vinmax ´ ƒ sw
(9)
æ Vout ´ (Vinmax - Vout ) ö
çç
÷÷
Vinmax ´ L ´ ƒ sw
è
ø
2
ILrms = IO +
12
Iripple
ILpeak = Iout +
2
2
(10)
(11)
The current flowing through the inductor is the inductor ripple current plus the output current. During power up,
faults or transient load conditions, the inductor current can increase above the calculated peak inductor current
level calculated above. In transient conditions, the inductor current can increase up to the switch current limit of
the device. For this reason, the most conservative approach is to specify an inductor with a saturation current
rating equal to or greater than the switch current limit rather than the peak inductor current.
8.2.2.2 Output Capacitor Selection
The three primary considerations for selecting the value of the output capacitor are:
• Output capacitor determines the modulator pole
• Output voltage ripple
• How the regulator responds to a large change in load current
The output capacitance must be selected based on the most stringent of these three criteria.
The desired response to a large change in the load current is the first criterion. The output capacitor needs to
supply the load with current when the regulator cannot. This situation would occur if there are desired hold-up
times for the regulator where the output capacitor must hold the output voltage above a certain level for a
specified amount of time after the input power is removed. The regulator is also temporarily not able to supply
sufficient output current if there is a large, fast increase in the current needs of the load such as a transition from
no load to full load. The regulator usually needs two or more clock cycles for the control loop to see the change
in load current and output voltage and adjust the duty cycle to react to the change. The output capacitor must be
sized to supply the extra current to the load until the control loop responds to the load change. The output
capacitance must be large enough to supply the difference in current for 2 clock cycles while only allowing a
tolerable amount of droop in the output voltage. Equation 12 shows the minimum output capacitance necessary
to accomplish this.
2 ´ DIout
Co =
ƒ sw ´ DVout
where
•
•
•
30
ΔIout is the change in output current
ƒsw is the regulators switching frequency
ΔVout is the allowable change in the output voltage
Submit Documentation Feedback
(12)
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
Equation 13 calculates the minimum output capacitance needed to meet the output voltage ripple specification.
1
1
Co >
´
8 ´ ƒ sw Voripple
Ioripple
where
•
•
•
ƒsw is the switching frequency
Voripple is the maximum allowable output voltage ripple
Ioripple is the inductor ripple current
(13)
Equation 14 calculates the maximum ESR an output capacitor can have to meet the output voltage ripple
specification.
Voripple
Re sr <
Ioripple
(14)
Additional capacitance deratings for aging, temperature, and DC bias should be factored in, which increases this
minimum value. Capacitors generally have limits to the amount of ripple current they can handle without failing or
producing excess heat. The user must specify an output capacitor that can support the inductor ripple current.
Some capacitor data sheets specify the root mean square (RMS) value of the maximum ripple current. Use
Equation 15 to calculate the RMS ripple current the output capacitor needs to support.
Icorms =
Vout ´ (Vinmax - Vout )
12 ´ Vinmax ´ L ´ ƒ sw
(15)
8.2.2.3 Input Capacitor Selection
The TPS65263-1Q1 requires a high-quality ceramic, type X5R or X7R, input decoupling capacitor of at least 10
µF of effective capacitance on the PVIN input voltage pins. In some applications, additional bulk capacitance may
also be required for the PVIN input. The effective capacitance includes any DC bias effects. The voltage rating of
the input capacitor must be greater than the maximum input voltage. The capacitor must also have a ripple
current rating greater than the maximum input current ripple of the TPS65263-1Q1. The input ripple current can
be calculated using Equation 16.
Iinrms = Iout ´
(Vinmin - Vout )
Vout
´
Vinmin
Vinmin
(16)
The value of a ceramic capacitor varies significantly over temperature and the amount of DC bias applied to the
capacitor. The capacitance variations due to temperature can be minimized by selecting a dielectric material that
is stable over temperature. X5R and X7R ceramic dielectrics are usually selected for power regulator capacitors
because they have a high capacitance-to-volume ratio and are fairly stable over temperature. The output
capacitor must also be selected with the DC bias taken into account. The capacitance value of a capacitor
decreases as the DC bias across a capacitor increases. The input capacitance value determines the input ripple
voltage of the regulator. Use Equation 17 to calculate the input voltage ripple.
I
´ 0.25
DVin = out max
Cin ´ ƒ sw
(17)
8.2.2.4 Loop Compensation
The TPS65263-1Q1 incorporates a peak current mode control scheme. The error amplifier is a transconductance
amplifier with a gain of 300 µS. A typical type II compensation circuit adequately delivers a phase margin
between 40° and 90°. Cb adds a high-frequency pole to attenuate high-frequency noise when needed. To
calculate the external compensation components, follow these steps.
1. Select switching frequency, ƒsw, that is appropriate for application depending on L and C sizes, output ripple,
EMI, and so forth. Switching frequency between 500 kHz to 1 MHz gives best trade-off between performance
and cost. To optimize efficiency, lower switching frequency is desired.
2. Set up crossover frequency, ƒc, which is typically between 1/5 and 1/20 of ƒsw.
3. RC can be determined by:
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
31
TPS65263-1Q1
SLVSDY9 – MARCH 2017
RC =
www.ti.com
2p ´ ƒc ´ Vo ´ Co
Gm-EA ´ Vref ´ Gm-PS
where
•
•
Gm_EA is the error amplifier gain (300 µS).
Gm_PS is the power stage voltage to current conversion gain (7.4 A/V).
(18)
æ
ç ƒp =
4. Calculate CC by placing a compensation zero at or before the dominant pole è
R ´ Co
CC = L
RC
1
Co ´ RL
ö
÷
´ 2p ø .
(19)
5. Optional Cb can be used to cancel the zero from the ESR associated with CO.
R
´ Co
Cb = ESR
RC
(20)
6. Type III compensation can be implemented with the addition of one capacitor, C1. This allows for slightly
higher loop bandwidths and higher phase margins. If used, calculate C1 from Equation 21.
C1 =
1
S î 51 u ¦C
(21)
LX
VOUT
iL
Current Sense
I/V Converter
RESR
RL
Gm _ PS
7.4 A / V
Co
R1
±
COMP
C1
FB
Vfb
EA
+
Vref
0.6 V
R2
Rc
Gm _ EA
300 uS
Cb
Cc
Figure 43. DC/DC Loop Compensation
32
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
8.2.3 Application Curves
Iout = 3 A
Iout = 2 A
Figure 44. BUCK1, Soft-Start
Iout = 2 A
Figure 45. BUCK2, Soft-Start
Iout = 3 A
Figure 46. BUCK3, Soft-Start
Figure 47. BUCK1, Output Voltage Ripple
Iout = 2 A
Iout = 2 A
Figure 48. BUCK2, Output Voltage Ripple
Figure 49. BUCK3, Output Voltage Ripple
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
33
TPS65263-1Q1
SLVSDY9 – MARCH 2017
0.75 to 1.5 A
www.ti.com
SR = 0.25 A/µs
1.5 to 2.25 A
Figure 50. BUCK1, Load Transient
0.5 to 1.0 A
SR = 0.25 A/µs
Figure 51. BUCK1, Load Transient
1.0 to 1.5 A
Figure 52. BUCK2, Load Transient
0.5 to 1.0 A
SR = 0.25 A/µs
SR = 0.25 A/µs
Figure 53. BUCK2, Load Transient
1.0 to 1.5 A
Figure 54. BUCK3, Load Transient
34
SR = 0.25 A/µs
Submit Documentation Feedback
SR = 0.25 A/µs
Figure 55. BUCK3, Load Transient
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
Figure 56. BUCK1, Hiccup and Recovery
Figure 57. BUCK2, Hiccup and Recovery
Figure 58. BUCK3, Hiccup and Recovery
Figure 60. VID2 from 00 to 7F, SR = 10 mV/Cycle
Figure 59. PGOOD
Figure 61. VID2 from 7F to 00, SR = 10 mV/Cycle
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
35
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
Figure 62. 180° Out-of-Phase
Figure 63. Synchronization With External Clock
VIN = 12 V, VOUT1 = 1.5 V/3 A, VOUT2 = 1.2 V/2 A,
VOUT3 = 2.5 V/2 A,
TA = 26.8°C EVM condition 4 layers, 75 mm × 75 mm
Figure 64. Operation at VIN Drop to 2.5 V
36
Figure 65. Thermal Signature of TPS65263-1Q1EVM
Operating
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
9 Power Supply Recommendations
The devices are designed to operate from an input voltage supply range between 4 and 18 V. This input power
supply should be well regulated. If the input supply is located more than a few inches from the TPS65263-1Q1
converter, additional bulk capacitance may be required in addition to the ceramic bypass capacitors. An
electrolytic capacitor with a value of 47 µF is a typical choice.
10 Layout
10.1 Layout Guidelines
Figure 66 shows the TPS65263-1Q1 on a 2-layer PCB.
Layout is a critical portion of good power-supply design. See Figure 66 for a PCB layout example. The top
contains the main power traces for PVIN, VOUT, and LX. The top layer also has connections for the remaining
pins of the TPS65263-1Q1 and a large top-side area filled with ground. The top-layer ground area should be
connected to the bottom layer ground using vias at the input bypass capacitor, the output filter capacitor, and
directly under the TPS65263-1Q1 device to provide a thermal path from the exposed thermal pad land to ground.
The bottom layer acts as ground plane connecting analog ground and power ground.
For operation at full rated load, the top-side ground area together with the bottom-side ground plane must
provide adequate heat dissipating area. Several signals paths conduct fast changing currents or voltages that
can interact with stray inductance or parasitic capacitance to generate noise or degrade the power supplies'
performance. To help eliminate these problems, bypass the PVIN pin to ground with a low-ESR ceramic bypass
capacitor with X5R or X7R dielectric. Take care to minimize the loop area formed by the bypass capacitor
connections, the PVIN pins, and the ground connections. The VIN pin must also be bypassed to ground using a
low-ESR ceramic capacitor with X5R or X7R dielectric.
Because the LX connection is the switching node, the output inductor should be located close to the LX pins, and
the area of the PCB conductor minimized to prevent excessive capacitive coupling. The output filter capacitor
ground should use the same power ground trace as the PVIN input bypass capacitor. Try to minimize this
conductor length while maintaining adequate width. The small signal components should be grounded to the
analog ground path.
The FB and COMP pins are sensitive to noise so the resistors and capacitors should be located as close as
possible to the IC and routed with minimal lengths of trace. The additional external components can be placed
approximately as shown.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
37
TPS65263-1Q1
SLVSDY9 – MARCH 2017
www.ti.com
10.2 Layout Example
VOUT1
SS3
FB3
COMP3
PGOOD
ROSC
FB1
SS1
COMP1
VOUT3
BST3
BST1
LX2
EN2
BST2
PVIN
SS2
PGND2
EN1
COMP2
V7V
FB2
PVIN2
VOUT2
PVIN3
VIN
AGND
PVIN1
SCL
PGND3
EN3
VIN
LX3
PGND1
SDA
PVIN
LX1
VOUT2
TOPSIDE
GROUND
AREA
0.010-inch Diameter
Thermal VIA to Ground Plane
VIA to Ground Plane
Figure 66. PCB Layout
38
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
TPS65263-1Q1
www.ti.com
SLVSDY9 – MARCH 2017
11 Device and Documentation Support
11.1 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
11.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
11.3 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
11.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: TPS65263-1Q1
39
PACKAGE OPTION ADDENDUM
www.ti.com
26-May-2017
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Op Temp (°C)
Device Marking
(4/5)
TPS65263-1QRHBRQ1
ACTIVE
VQFN
RHB
32
3000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 125
TPS
263-1Q
TPS65263-1QRHBTQ1
ACTIVE
VQFN
RHB
32
250
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 125
TPS
263-1Q
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
26-May-2017
OTHER QUALIFIED VERSIONS OF TPS65263-1Q1 :
• Automotive: TPS65263-Q1
NOTE: Qualified Version Definitions:
• Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
3-Jun-2017
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
TPS65263-1QRHBRQ1
VQFN
RHB
32
3000
330.0
12.4
5.3
5.3
1.1
8.0
12.0
Q2
TPS65263-1QRHBTQ1
VQFN
RHB
32
250
180.0
12.4
5.3
5.3
1.1
8.0
12.0
Q2
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
3-Jun-2017
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
TPS65263-1QRHBRQ1
VQFN
RHB
32
3000
367.0
367.0
35.0
TPS65263-1QRHBTQ1
VQFN
RHB
32
250
210.0
185.0
35.0
Pack Materials-Page 2
GENERIC PACKAGE VIEW
RHB 32
VQFN - 1 mm max height
PLASTIC QUAD FLATPACK - NO LEAD
5 x 5, 0.5 mm pitch
Images above are just a representation of the package family, actual package may vary.
Refer to the product data sheet for package details.
4224745/A
www.ti.com
PACKAGE OUTLINE
RHB0032E
VQFN - 1 mm max height
SCALE 3.000
PLASTIC QUAD FLATPACK - NO LEAD
5.1
4.9
A
B
PIN 1 INDEX AREA
(0.1)
5.1
4.9
SIDE WALL DETAIL
OPTIONAL METAL THICKNESS
20.000
C
1 MAX
SEATING PLANE
0.05
0.00
0.08 C
2X 3.5
(0.2) TYP
3.45 0.1
9
EXPOSED
THERMAL PAD
16
28X 0.5
8
17
2X
3.5
SEE SIDE WALL
DETAIL
SYMM
33
32X
24
1
PIN 1 ID
(OPTIONAL)
32
0.3
0.2
0.1
0.05
C A B
C
25
SYMM
32X
0.5
0.3
4223442/B 08/2019
NOTES:
1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing
per ASME Y14.5M.
2. This drawing is subject to change without notice.
3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance.
www.ti.com
EXAMPLE BOARD LAYOUT
RHB0032E
VQFN - 1 mm max height
PLASTIC QUAD FLATPACK - NO LEAD
( 3.45)
SYMM
32
25
32X (0.6)
1
24
32X (0.25)
(1.475)
28X (0.5)
33
SYMM
(4.8)
( 0.2) TYP
VIA
8
17
(R0.05)
TYP
9
(1.475)
16
(4.8)
LAND PATTERN EXAMPLE
SCALE:18X
0.07 MIN
ALL AROUND
0.07 MAX
ALL AROUND
SOLDER MASK
OPENING
METAL
SOLDER MASK
OPENING
METAL UNDER
SOLDER MASK
NON SOLDER MASK
DEFINED
(PREFERRED)
SOLDER MASK
DEFINED
SOLDER MASK DETAILS
4223442/B 08/2019
NOTES: (continued)
4. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature
number SLUA271 (www.ti.com/lit/slua271).
5. Vias are optional depending on application, refer to device data sheet. If any vias are implemented, refer to their locations shown
on this view. It is recommended that vias under paste be filled, plugged or tented.
www.ti.com
EXAMPLE STENCIL DESIGN
RHB0032E
VQFN - 1 mm max height
PLASTIC QUAD FLATPACK - NO LEAD
4X ( 1.49)
(0.845)
(R0.05) TYP
32
25
32X (0.6)
1
24
32X (0.25)
28X (0.5)
(0.845)
SYMM
33
(4.8)
17
8
METAL
TYP
16
9
SYMM
(4.8)
SOLDER PASTE EXAMPLE
BASED ON 0.125 mm THICK STENCIL
EXPOSED PAD 33:
75% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE
SCALE:20X
4223442/B 08/2019
NOTES: (continued)
6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate
design recommendations.
www.ti.com
IMPORTANT NOTICE AND DISCLAIMER
TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE
DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”
AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY
IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD
PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate
TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable
standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you
permission to use these resources only for development of an application that uses the TI products described in the resource. Other
reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third
party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims,
damages, costs, losses, and liabilities arising out of your use of these resources.
TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on
ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable
warranties or warranty disclaimers for TI products.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2019, Texas Instruments Incorporated
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Related manuals

Download PDF

advertising