Texas Instruments | LMZ14203 SIMPLE SWITCHER® 6-V to 42-V, 3-A Power Module in Leaded SMT-TO Package (Rev. S) | Datasheet | Texas Instruments LMZ14203 SIMPLE SWITCHER® 6-V to 42-V, 3-A Power Module in Leaded SMT-TO Package (Rev. S) Datasheet

Texas Instruments LMZ14203 SIMPLE SWITCHER® 6-V to 42-V, 3-A Power Module in Leaded SMT-TO Package (Rev. S) Datasheet
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LMZ14203
SNVS632S – DECEMBER 2009 – REVISED JULY 2017
LMZ14203 SIMPLE SWITCHER® 6-V to 42-V, 3-A Power Module in Leaded SMT-TO
Package
1 Features
2 Applications
•
•
1
•
•
•
•
•
•
•
•
•
•
•
Integrated Shielded Inductor & Simple PCB
Layout
Flexible Start-Up Sequencing Using External SoftStart and Precision Enable
Protection Against Inrush Currents and Faults
Such as Input UVLO and Output Short Circuit
–40°C to 125°C Junction Temperature Range
Single Exposed Pad and Standard Pinout for Easy
Mounting and Manufacturing
Fast Transient Response for Powering FPGAs
and ASICs
Low Output Voltage Ripple
Pin-to-Pin Compatible Family:
– LMZ1420x (42 V Maximum 3 A, 2 A, 1 A)
– LMZ1200x (20 V Maximum 3 A, 2 A, 1 A)
Fully Enabled for WEBENCH® Power Designer
Electrical Specifications
– 18-W Maximum Total Output Power
– Up to 3-A Output Current
– Input Voltage Range 6 V to 42 V
– Output Voltage Range 0.8 V to 6 V
– Efficiency up to 90%
Performance Benefits
– Operates at High Ambient Temperature With
No Thermal Derating
– High Efficiency Reduces System Heat
Generation
– Low Radiated Emissions (Electromagnetic
Interference [EMI]) Tested With EN55022
Class B Standard
– Passes 10-V/m Radiated Immunity EMI Test
Standard EN61000 4-3
Create a Custom Design Using the LMZ14203
With the WEBENCH® Power Designer
Simplified Application Schematic
•
•
Point of Load Conversions From 12-V and 24-V
Input Rail
Space Constrained and High Thermal
Requirement Applications
Negative Output Voltage Applications
(See AN-2027 SNVA425)
3 Description
The LMZ14203 SIMPLE SWITCHER power module
is an easy-to-use step-down DC-DC solution that can
drive up to 3-A load with exceptional power
conversion efficiency, line and load regulation, and
output accuracy. The LMZ14203 is available in an
innovative
package
that
enhances
thermal
performance and allows for hand or machine
soldering.
The LMZ14203 can accept an input voltage rail
between 6 V and 42 V and deliver an adjustable and
highly accurate output voltage as low as 0.8 V. The
LMZ14203 only requires three external resistors and
four external capacitors to complete the power
solution. The LMZ14203 is a reliable and robust
design with the following protection features: thermal
shutdown, input UVLO, output overvoltage protection,
short-circuit protection, output current limit, and
allows start-up into a prebiased output. A single
resistor adjusts the switching frequency up to 1 MHz.
Device Information(1)(2)
PART NUMBER
10.16 mm × 9.85 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
(2) Peak reflow temperature equals 245°C. See SNAA214 for
more details.
Efficiency 12-V Input at 25°C
100
95
VOUT
90
EFFICIENCY (%)
FB
SS
EN
GND
VIN
RON
BODY SIZE (NOM)
TO-PMOD (7)
LMZ14203
VIN
PACKAGE
LMZ14203
VOUT
CFF
RON
RFBT
Enable
5.0
3.3
2.5
85
80
1.8
1.5
1.2
75
70
0.8
65
60
CIN
CSS
RFBB
COUT
55
25°C
50
0
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
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.
LMZ14203
SNVS632S – DECEMBER 2009 – REVISED JULY 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
3
6.1
6.2
6.3
6.4
6.5
6.6
3
4
4
4
4
6
Detailed Description ............................................ 10
7.1
7.2
7.3
7.4
8
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics .............................................
Overview .................................................................
Functional Block Diagram .......................................
Feature Description.................................................
Device Functional Modes........................................
10
10
10
11
Application and Implementation ........................ 12
8.1 Application Information............................................ 12
8.2 Typical Application .................................................. 12
9 Power Supply Recommendations...................... 18
10 Layout................................................................... 18
10.1 Layout Guidelines .................................................
10.2 Layout Example ....................................................
10.3 Power Dissipation and Board Thermal
Requirements...........................................................
10.4 Power Module SMT Guidelines ............................
18
19
20
20
11 Device and Documentation Support ................. 22
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
Custom Design With WEBENCH® Tools .............
Device Support......................................................
Documentation Support ........................................
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
22
22
22
22
22
23
23
23
12 Mechanical, Packaging, and Orderable
Information ........................................................... 23
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision R (October 2015) to Revision S
Page
•
Changed equation 9 to put a bracket around fsw*delta VIN ................................................................................................ 15
•
Changed equation 10 to put a bracket around VIN and RON2 ............................................................................................... 16
Changes from Revision Q (August 2015) to Revision R
•
Added this new bullet to the Power Module SMT Guidelines .............................................................................................. 20
Changes from Revision P (May 2015) to Revision Q
•
Page
Page
Changed the title of the document ......................................................................................................................................... 1
Changes from Revision O (October 2013) to Revision P
Page
•
Added ESD Rating table, Thermal Information table, Feature Description section, Device Functional Modes,
Application and Implementation section, Power Supply Recommendations section, Layout section, Device and
Documentation Support section, and Mechanical, Packaging, and Orderable Information section ..................................... 1
•
Removed Easy-to-Use Pin Package image ........................................................................................................................... 1
Changes from Revision N (March 2013) to Revision O
Page
•
Changed 12 mils................................................................................................................................................................... 18
•
Changed 12 mils................................................................................................................................................................... 20
•
Added Power Module SMT Guidelines................................................................................................................................. 20
2
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SNVS632S – DECEMBER 2009 – REVISED JULY 2017
5 Pin Configuration and Functions
NDW Package
7-Pin TO-PMOD
Top View
Exposed Pad
Connect to GND
7
6
5
4
3
2
1
VOUT
FB
SS
GND
EN
RON
VIN
Pin Functions
PIN
NAME
NO.
TYPE
DESCRIPTION
EN
3
Analog
Enable. Input to the precision enable comparator. Rising threshold is 1.18 V nominal; 90 mV
hysteresis nominal. Maximum recommended input level is 6.5 V.
FB
6
Analog
Feedback. Internally connected to the regulation, overvoltage, and short-circuit comparators. The
regulation reference point is 0.8 V at this input pin. Connected the feedback resistor divider between
the output and ground to set the output voltage.
GND
4
Ground
Ground. Reference point for all stated voltages. Must be externally connected to exposed thermal
pad.
RON
2
Analog
ON-time resistor. An external resistor between this pin and the VIN pin sets the ON-time of the
application. Typical values range from 25 kΩ to 124 kΩ.
SS
5
Analog
Soft-start. An internal 8-µA current source charges an external capacitor to produce the soft-start
function. This node is discharged at 200 µA during disable, overcurrent, thermal shutdown and
internal UVLO conditions.
VIN
1
Power
Supply input. Nominal operating range is 6 V to 42 V . A small amount of internal capacitance is
contained within the package assembly. Additional external input capacitance is required between
this pin and exposed pad.
VOUT
7
Power
Output voltage. Output from the internal inductor. Connect the output capacitor between this pin and
exposed pad.
Thermal
Pad
—
Ground
Exposed thermal pad. Internally connected to pin 4. Used to dissipate heat from the package during
operation. Must be electrically connected to pin 4 external to the package.
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1) (2)
MIN
MAX
UNIT
VIN, RON to GND
–0.3
43.5
V
EN, FB, SS to GND
–0.3
7
V
Junction Temperature
150
°C
Peak Reflow Case Temperature (30 sec)
245
°C
150
°C
Storage Temperature
(1)
(2)
–65
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.
For soldering specifications, refer to the following document: Absolute Maximum Ratings for Soldering (SNOA549).
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SNVS632S – DECEMBER 2009 – REVISED JULY 2017
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6.2 ESD Ratings
V(ESD)
(1)
VALUE
UNIT
±2000
V
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
Electrostatic discharge
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) (1)
MIN
MAX
VIN
6
42
V
EN
0
6.5
V
−40
125
°C
Operation Junction Temperature
(1)
UNIT
Absolute Maximum Ratings are limits beyond which damage to the device may occur. Recommended Operating Ratings are conditions
under which operation of the device is intended to be functional. For ensured specifications and test conditions, see the Electrical
Characteristics.
6.4 Thermal Information
LMZ14203
THERMAL METRIC
(1)
NDW (TO-PMOD)
UNIT
7 PINS
RθJA
Junction-to-ambient
thermal resistance
RθJC(top)
Junction-to-case (top)
thermal resistance
(1)
4-layer JEDEC Printed Circuit Board, No air flow
19.3
2-layer JEDEC Printed Circuit Board, No air flow
21.5
No air flow
1.9
°C/W
°C/W
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
6.5 Electrical Characteristics
TJ = 25°C unless otherwise noted. Minimum and maximum limits are ensured through test, design or statistical correlation.
Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless
otherwise stated the following conditions apply: VIN = 24 V, Vout = 3.3 V
PARAMETER
TEST CONDITIONS
MIN (1)
TYP (2)
MAX (1)
UNIT
SYSTEM PARAMETERS
Enable Control (3)
VEN
EN threshold trip
point
VEN-HYS
VEN rising
TJ = 25°C
over the junction temperature (TJ)
range of –40°C to +125°C
EN threshold
hysteresis
VEN falling
SS source current
VSS = 0V
1.18
1.1
1.25
90
V
mV
Soft Start
ISS
TJ = 25°C
over the junction temperature (TJ)
range of –40°C to +125°C
ISS-DIS
8
5
SS discharge
current
11
–200
µA
µA
Current Limit
ICL
(1)
(2)
(3)
4
Current limit
threshold
DC average
VIN= 12 V to 24 V
TJ = 25°C
over the junction temperature (TJ)
range of –40°C to +125°C
4.2
3.2
5.25
A
Minimum and maximum limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through
correlation using Statistical Quality Control (SQC) methods. Limits are used to calculate Average Outgoing Quality Level (AOQL).
Typical numbers are at 25°C and represent the most likely parametric norm.
EN 55022:2006, +A1:2007, FCC Part 15 Subpart B: 2007. See AN-2024 and layout for information on device under test.
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Electrical Characteristics (continued)
TJ = 25°C unless otherwise noted. Minimum and maximum limits are ensured through test, design or statistical correlation.
Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless
otherwise stated the following conditions apply: VIN = 24 V, Vout = 3.3 V
PARAMETER
TEST CONDITIONS
MIN (1)
TYP (2)
MAX (1)
UNIT
ON/OFF Timer
tON-MIN
ON timer minimum
pulse width
150
ns
tOFF
OFF timer pulse
width
260
ns
Regulation and Overvoltage Comparator
VFB
In-regulation
feedback voltage
VSS > 0.8 V
TJ = 25°C
TJ = –40°C to 125°C
over the junction temperature (TJ)
IO = 3 A
range of –40°C to +125°C
VSS > 0.8 V
TJ = 25°C
IO = 10 mA
VFB-OV
0.804
0.784
0.786
0.825
0.802
0.818
V
V
Feedback
overvoltage
protection threshold
0.92
V
IFB
Feedback input bias
current
5
nA
IQ
Nonswitching Input
Current
VFB= 0.86 V
1
mA
ISD
Shut Down
Quiescent Current
VEN= 0 V
25
μA
165
°C
15
°C
Thermal Characteristics
TSD
Thermal Shutdown
Rising
TSD-HYST
Thermal shutdown
hysteresis
Falling
PERFORMANCE PARAMETERS
ΔVO
Output Voltage
Ripple
8
ΔVO/ΔVIN Line Regulation
VIN = 12 V to 42 V, IO= 3 A
ΔVO/IOUT
Load Regulation
VIN = 24 V
η
Efficiency
VIN = 24 V VO = 3.3 V IO = 1 A
92%
η
Efficiency
VIN = 24 V VO = 3.3 V IO = 3 A
85%
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PP
0.01%
1.5
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mV
mV/A
5
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SNVS632S – DECEMBER 2009 – REVISED JULY 2017
www.ti.com
6.6 Typical Characteristics
Unless otherwise specified, the following conditions apply: VIN = 24 V; CIN = 10-µF X7R Ceramic; CO = 100-µF X7R Ceramic;
TA = 25°C for efficiency curves and waveforms.
2.5
100
95
2
3.3
2.5
1.8
1.5
1.2
80
75
DISSIPATION (W)
EFFICIENCY (%)
90
85
70
0.8
65
60
3.3
2.5
1.8
1.5
1
1.5
1.2
0.8
0.5
25°C
55
25°C
50
0
0.5
1
1.5
2
2.5
0
3
0
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Figure 1. Efficiency 6-V Input at 25°C
Figure 2. Dissipation 6-V Input at 25°C
100
2.5
95
2
5.0
3.3
2.5
85
80
DISSIPATION (W)
EFFICIENCY (%)
90
1.8
1.5
1.2
75
70
0.8
65
5.0
3.3
2.5
1.5
1.8
1
1.5
1.2
0.8
0.5
60
25° C
55
25°C
50
0
0
0.5
1
1.5
2
2.5
0
3
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Figure 3. Efficiency 12-V Input at 25°C
Figure 4. Dissipation 12-V Input at 25°C
100
2.5
95
5.0
2
5.0
85
80
3.3
2.5
75
1.8
3.3
DISSIPATION (W)
EFFICIENCY (%)
90
70
65
1.5
2.5
1
1.8
0.5
60
25°C
55
25°C
50
0
6
0
0.5
1
1.5
2
2.5
3
0
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT(A)
OUTPUT CURRENT (A)
Figure 5. Efficiency 24-V Input at 25°C
Figure 6. Dissipation 24-V Input at 25°C
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Typical Characteristics (continued)
Unless otherwise specified, the following conditions apply: VIN = 24 V; CIN = 10-µF X7R Ceramic; CO = 100-µF X7R Ceramic;
TA = 25°C for efficiency curves and waveforms.
2.5
100
5.0
95
2
3.3
5.0
85
DISSIPATION (W)
EFFICIENCY (%)
90
3.3
80
75
70
65
1.5
1
0.5
60
25°C
55
25°C
50
0
0
0.5
1
1.5
2
2.5
0
3
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Figure 7. Efficiency 36-V Input at 25°C
Figure 8. Dissipation 36-V Input at 25°C
100
3
95
2.5
85
DISSIPATION (W)
EFFICIENCY (%)
90
3.3
2.5
80
75
1.8
1.5
1.2
70
65
60
1.5
1.5
1.2
1
0.8
85°C
85°C
0
50
0.5
0
1.8
0.5
0.8
55
3.3
2.5
2
1
1.5
2
0
3
2.5
0.5
1
1.5
2.5
3
Figure 10. Dissipation 6-V Input at 85°C
Figure 9. Efficiency 6-V Input at 85°C
100
3
95
5.0
2.5
85
5.0
80
3.3
2.5
75
DISSIPATION (W)
90
EFFICIENCY (%)
2
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
1.8
1.5
70
1.2
65
60
0.8
3.3
2.5
2
1.8
1.5
1.5
1.2
1
0.8
0.5
85°C
55
85°C
50
0
0.5
0
1
1.5
2
2.5
3
0
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Figure 11. Efficiency 8-V Input at 85°C
Figure 12. Dissipation 8-V Input at 85°C
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Typical Characteristics (continued)
Unless otherwise specified, the following conditions apply: VIN = 24 V; CIN = 10-µF X7R Ceramic; CO = 100-µF X7R Ceramic;
TA = 25°C for efficiency curves and waveforms.
3
100
95
2.5
90
DISSIPATION (W)
85
EFFICIENCY (%)
5.0
3.3
5.0
3.3
80
2.5
1.8
1.5
75
70
1.2
65
2
2.5
1.8
1.5
1.5
1.2
1
0.8
0.8
60
0.5
85°C
55
85°C
50
0
0
0.5
1
1.5
2
2.5
3
0
0.5
1
1.5
2
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Figure 14. Dissipation 12-V Input at 85°C
Figure 13. Efficiency 12-V Input at 85°C
3
100
95
5.0
2.5
90
3.3
5.0
85
DISSIPATION (W)
EFFICIENCY (%)
2.5
3.3
80
2.5
75
1.8
70
65
60
2
1.5
2.5
1.8
1
0.5
85°C
55
85°C
50
0
0.5
0
1
1.5
2
2.5
0
3
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Figure 15. Efficiency 24-V Input at 85°C
Figure 16. Dissipation 24-V Input at 85°C
100
3
5.0
95
2.5
85
5.0
80
3.3
DISSIPATION (W)
EFFICIENCY (%)
90
75
70
65
60
1.5
1
0.5
55
85°C
0
0.5
85°C
0
50
1
1.5
2
2.5
3
0
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Figure 17. Efficiency 36-V Input at 85°C
8
3.3
2
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Figure 18. Dissipation 36-V Input at 85°C
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Typical Characteristics (continued)
Unless otherwise specified, the following conditions apply: VIN = 24 V; CIN = 10-µF X7R Ceramic; CO = 100-µF X7R Ceramic;
TA = 25°C for efficiency curves and waveforms.
3.36
OUTPUT VOLTAGE (V)
3.34
3.32
20
3.3
12 15
3.28
42
36
8
6
25°C
3.26
0
0.5
1
1.5
2
2.5
3
OUTPUT CURRENT (A)
Figure 20. Output Ripple
24 VIN 3.3 VO 3 A, BW = 200 MHz
Figure 19. Line and Load Regulation at 25°C
3.5
12Vin
OUTPUT CURRENT (A)
3
2.5
36VIN
6Vin
2
24Vin
6Vin
1.5
1
12Vin
JA = 19.6°C/W
0.5
VOUT = 3.3V
0
50
60
70
80
90
100 110 120
AMBIENT TEMPERATURE (°C)
Figure 21. Transient Response
24 VIN 3.3 VO 0.6-A to 3-A Step
Figure 22. Thermal Derating VOUT = 3.3 V
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7 Detailed Description
7.1 Overview
The LMZ14203 power module is an easy-to-use step-down DC-DC solution that can drive up to 3-A load with
exceptional power conversion efficiency, line and load regulation, and output accuracy.
7.2 Functional Block Diagram
Vin
VIN 1
Linear reg
Cvcc
5
CIN
SS
Css
CBST
3
EN
RON
2
VOUT 7
RON
Timer
CFF
6
6.8 éH
VO
Co
FB
RFBT
RFBB
0.47 éF
Regulator IC
Internal
Passives
GND
4
7.3 Feature Description
7.3.1 COT Control Circuit Overview
Constant ON-Time control is based on a comparator and an ON-time one shot, with the output voltage feedback
compared with an internal 0.8-V reference. If the feedback voltage is below the reference, the main MOSFET is
turned on for a fixed ON-time determined by a programming resistor RON. RON is connected to VIN such that ONtime is reduced with increasing input supply voltage. Following this ON-time, the main MOSFET remains off for a
minimum of 260 ns. If the voltage on the feedback pin falls below the reference level again the ON-time cycle is
repeated. Regulation is achieved in this manner.
7.3.2 Output Overvoltage Comparator
The voltage at FB is compared to a 0.92-V internal reference. If FB rises above 0.92 V the ON-time is
immediately terminated. This condition is known as overvoltage protection (OVP). It can occur if the input voltage
is increased very suddenly or if the output load is decreased very suddenly. Once OVP is activated, the top
MOSFET ON-times will be inhibited until the condition clears. Additionally, the synchronous MOSFET will remain
on until inductor current falls to zero.
7.3.3 Current Limit
Current limit detection is carried out during the OFF-time by monitoring the current in the synchronous MOSFET.
Referring to the Functional Block Diagram, when the top MOSFET is turned off, the inductor current flows
through the load, the PGND pin and the internal synchronous MOSFET. If this current exceeds 4.2 A (typical) the
current limit comparator disables the start of the next ON-time period. The next switching cycle will occur only if
the FB input is less than 0.8 V and the inductor current has decreased below 4.2 A. Inductor current is monitored
during the period of time the synchronous MOSFET is conducting. So long as inductor current exceeds 4.2 A,
further ON-time intervals for the top MOSFET will not occur. Switching frequency is lower during current limit due
to the longer OFF-time.
NOTE
Current limit is dependent on both duty cycle and temperature.
10
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Feature Description (continued)
7.3.4 Thermal Protection
The junction temperature of the LMZ14203 should not be allowed to exceed its maximum ratings. Thermal
protection is implemented by an internal Thermal Shutdown circuit which activates at 165 °C (typical) causing the
device to enter a low power standby state. In this state the main MOSFET remains off causing VO to fall, and
additionally the CSS capacitor is discharged to ground. Thermal protection helps prevent catastrophic failures for
accidental device overheating. When the junction temperature falls back below 145°C (typical hysteresis = 20 °C)
the SS pin is released, VO rises smoothly, and normal operation resumes.
Applications requiring maximum output current especially those at high input voltage may require application
derating at elevated temperatures.
7.3.5 Zero Coil Current Detection
The current of the lower (synchronous) MOSFET is monitored by a zero coil current detection circuit which
inhibits the synchronous MOSFET when its current reaches zero until the next ON-time. This circuit enables the
DCM operating mode, which improves efficiency at light loads.
7.3.6 Prebiased Start-Up
The LMZ14203 will properly start up into a prebiased output. This start-up situation is common in multiple rail
logic applications where current paths may exist between different power rails during the start-up sequence.
Figure 23 is a scope capture that shows proper behavior during this event.
Figure 23. Prebiased Start-Up
7.4 Device Functional Modes
7.4.1 Discontinuous Conduction and Continuous Conduction Modes
At light-load, the regulator operates in discontinuous conduction mode (DCM). With load currents above the
critical conduction point, it operates in continuous conduction mode (CCM). When operating in DCM the
switching cycle begins at zero amps inductor current; increases up to a peak value, and then recedes back to
zero before the end of the OFF-time. During the period of time that inductor current is zero, all load current is
supplied by the output capacitor. The next ON-time period starts when the voltage on the FB pin falls below the
internal reference. The switching frequency is lower in DCM and varies more with load current as compared to
CCM. Conversion efficiency in DCM is maintained because conduction and switching losses are reduced with
the smaller load and lower switching frequency.
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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 LMZ14203 is a step-down DC-to-DC power module. It is typically used to convert a higher DC voltage to a
lower DC voltage with a maximum output current of 3 A. The following design procedure can be used to select
components for the LMZ14203. Alternately, the WEBENCH software may be used to generate complete designs.
When generating a design, the WEBENCH software uses iterative design procedure and accesses
comprehensive databases of components. For more details, see www.ti.com.
8.2 Typical Application
U1
EP
Enable
VIN
VOUT
FB
SS
GND
EN
3.3VO @ 3A
7
6
5
4
VIN
2
1
3
RON
LMZ14203TZ
8V to 42V
RENT
68.1k
CFF
0.022 PF
RFBT
3.32k
RON
61.9k
RENB
11.8k
CIN1
1 PF
CIN2
10 PF
CSS
0.022 PF
RFBB
1.07k
CO1
1 PF
CO2
100 PF
Figure 24. Evaluation Board Schematic Diagram
8.2.1 Design Requirements
For this example the following application parameters exist.
• VIN Range = Up to 42 V
• VOUT = 0.8 V to 5 V
• IOUT = 3 A
Please refer to Table 1 for more information.
12
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Table 1. Component Value Combinations
VOUT (V)
RFBT (kΩ)
VIN (V)
RFBB (kΩ)
RDS(on) (kΩ)
1.07
61.9
42
47.5
30
100
MIN
MAX
7.5
42
5
5.62
3.3
3.32
2.5
2.26
1.8
1.87
1.5
1.5
1
1.13
28
1.2
4.22
8.45
22.6
19
0.8
0
39.2
24.9
18
32.4
25
6
21
Table 2. List of Materials
Ref Des
Description
Case Size
Manufacturer
U1
SIMPLE SWITCHER
PFM-7
Texas Instruments
Manufacturer P/N
LMZ14203TZ
CIN1
1 µF, 50 V, X7R
1206
Taiyo Yuden
UMK316B7105KL-T
CIN2
10 µF, 50 V, X7R
1210
Taiyo Yuden
UMK325BJ106MM-T
CO1
1 µF, 50 V, X7R
1206
Taiyo Yuden
UMK316B7105KL-T
CO2
100 µF, 6.3 V, X7R
1210
Taiyo Yuden
JMK325BJ107MM-T
RFBT
3.32 kΩ
0603
Vishay Dale
CRCW06033K32FKEA
RFBB
1.07 kΩ
0603
Vishay Dale
CRCW06031K07FKEA
RON
61.9 kΩ
0603
Vishay Dale
CRCW060361k9FKEA
RENT
68.1 kΩ
0603
Vishay Dale
CRCW060368k1FKEA
RENB
11.8 kΩ
0603
Vishay Dale
CRCW060311k8FKEA
CFF
22 nF, ±10%, X7R, 16 V
0603
TDK
C1608X7R1H223K
CSS
22 nF, ±10%, X7R, 16 V
0603
TDK
C1608X7R1H223K
8.2.2 Detailed Design Procedure
8.2.2.1 Custom Design With WEBENCH® Tools
Click here to create a custom design using the LMZ14203 device with the WEBENCH® Power Designer.
1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements.
2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial.
3. Compare the generated design with other possible solutions from Texas Instruments.
The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time
pricing and component availability.
In most cases, these actions are available:
• Run electrical simulations to see important waveforms and circuit performance
• Run thermal simulations to understand board thermal performance
• Export customized schematic and layout into popular CAD formats
• Print PDF reports for the design, and share the design with colleagues
Get more information about WEBENCH tools at www.ti.com/WEBENCH.
8.2.2.2 Design Steps for the LMZ14203 Application
The LMZ14203 is fully supported by WEBENCH and offers the following: Component selection, electrical and
thermal simulations as well as the build-it board for a reduction in design time. The following list of steps can be
used to manually design the LMZ14203 application.
1. Select minimum operating VIN with enable divider resistors
2. Program VO with divider resistor selection
3. Program turnon time with soft-start capacitor selection
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4.
5.
6.
7.
8.
www.ti.com
Select CO
Select CIN
Set operating frequency with RON
Determine module dissipation
Lay out PCB for required thermal performance
8.2.2.2.1 Enable Divider, RENT and RENB Selection
The enable input provides a precise 1.18-V band-gap rising threshold to allow direct logic drive or connection to
a voltage divider from a higher enable voltage such as VIN. The enable input also incorporates 90 mV (typical) of
hysteresis resulting in a falling threshold of 1.09 V. The maximum recommended voltage into the EN pin is 6.5 V.
For applications where the midpoint of the enable divider exceeds 6.5 V, a small Zener diode can be added to
limit this voltage.
The function of this resistive divider is to allow the designer to choose an input voltage below which the circuit
will be disabled. This implements the feature of programmable under voltage lockout. This is often used in
battery powered systems to prevent deep discharge of the system battery. It is also useful in system designs for
sequencing of output rails or to prevent early turnon of the supply as the main input voltage rail rises at powerup. Applying the enable divider to the main input rail is often done in the case of higher input voltage systems
such as 24-V AC/DC systems where a lower boundary of operation should be established. In the case of
sequencing supplies, the divider is connected to a rail that becomes active earlier in the power-up cycle than the
LMZ14203 output rail. The two resistors should be chosen based on the following ratio:
RENT / RENB = (VIN UVLO / 1.18 V) – 1
(1)
The LMZ14203 demonstration and evaluation boards use 11.8 kΩ for RENB and 68.1 kΩ for RENT resulting in a
rising UVLO of 8 V. This divider presents 6.25 V to the EN input when the divider input is raised to 42 V.
The EN pin is internally pulled up to VIN and can be left floating for always-on operation.
8.2.2.2.2 Output Voltage Selection
Output voltage is determined by a divider of two resistors connected between VO and ground. The midpoint of
the divider is connected to the FB input. The voltage at FB is compared to a 0.8V internal reference. In normal
operation an ON-time cycle is initiated when the voltage on the FB pin falls below 0.8 V. The main MOSFET ONtime cycle causes the output voltage to rise and the voltage at the FB to exceed 0.8 V. As long as the voltage at
FB is above 0.8 V, ON-time cycles will not occur.
The regulated output voltage determined by the external divider resistors RFBT and RFBB is:
VO = 0.8 V × (1 + RFBT / RFBB)
(2)
Rearranging terms; the ratio of the feedback resistors for a desired output voltage is:
RFBT / RFBB = (VO / 0.8 V) - 1
(3)
These resistors should be chosen from values in the range of 1 kΩ to 10 kΩ.
For VO = 0.8 V the FB pin can be connected to the output directly so long as an output preload resistor remains
that draws more than 20 uA. Converter operation requires this minimum load to create a small inductor ripple
current and maintain proper regulation when no load is present.
A feed-forward capacitor is placed in parallel with RFBT to improve load step transient response. Its value is
usually determined experimentally by load stepping between DCM and CCM conduction modes and adjusting for
best transient response and minimum output ripple.
A table of values for RFBT , RFBB , CFF and RON is included in the applications schematic.
8.2.2.2.3 Soft-Start Capacitor Selection
Programmable soft-start permits the regulator to slowly ramp to its steady state operating point after being
enabled, thereby reducing current inrush from the input supply and slowing the output voltage rise-time to
prevent overshoot.
Upon turnon, after all UVLO conditions have been passed, an internal 8-uA current source begins charging the
external soft-start capacitor. The soft-start time duration to reach steady-state operation is given by the formula:
tSS = VREF × CSS / Iss = 0.8 V × CSS / 8 uA
14
(4)
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This equation can be rearranged as follows:
CSS = tSS × 8 μA / 0.8 V
(5)
Use of a 0.022-μF capacitor results in 2.2 ms soft-start duration. This is recommended as a minimum value.
As the soft-start input exceeds 0.8 V the output of the power stage will be in regulation. The soft-start capacitor
continues charging until it reaches approximately 3.8 V on the SS pin. Voltage levels between 0.8 V and 3.8 V
have no effect on other circuit operation. Note the following conditions will reset the soft-start capacitor by
discharging the SS input to ground with an internal 200-μA current sink.
•
•
•
•
The enable input being pulled low
Thermal shutdown condition
Overcurrent fault
Internal VCC UVLO (Approx 4-V input to VIN)
8.2.2.2.4 CO Selection
None of the required CO output capacitance is contained within the module. At a minimum, the output capacitor
must meet the worst case minimum ripple current rating of 0.5 × ILR P-P, as calculated in Equation 12 below.
Beyond that, additional capacitance will reduce output ripple so long as the ESR is low enough to permit it. A
minimum value of 10 μF is generally required. Experimentation will be required if attempting to operate with a
minimum value. Ceramic capacitors or other low ESR types are recommended. See AN-2024 SNVA422 for more
detail.
The following equation provides a good first pass approximation of CO for load transient requirements:
CO ≥ ISTEP × VFB × L × VIN / (4 × VO × (VIN – VO) × VOUT-TRAN)
(6)
Solving:
CO ≥ 3 A × 0.8 V × 6.8 μH × 24 V / (4 × 3.3 V × ( 24 V – 3.3 V) × 33 mV) ≥ 43 μF
(7)
The LMZ14203 demonstration and evaluation boards are populated with a 100-uF 6.3-V X5R output capacitor.
Locations for extra output capacitors are provided.
8.2.2.2.5 CIN Selection
The LMZ14203 module contains an internal 0.47-µF input ceramic capacitor. Additional input capacitance is
required external to the module to handle the input ripple current of the application. This input capacitance should
be very close to the module. Input capacitor selection is generally directed to satisfy the input ripple current
requirements rather than by capacitance value. Worst-case input ripple current rating is dictated by the equation:
I(CIN(RMS)) ≊ 1 /2 × IO × √(D / 1 – D)
where
•
D ≊ VO / VIN
(8)
(As a point of reference, the worst case ripple current will occur when the module is presented with full load
current and when VIN = 2 × VO).
Recommended minimum input capacitance is 10uF X7R ceramic with a voltage rating at least 25% higher than
the maximum applied input voltage for the application. TI also recommends to pay attention to the voltage and
temperature deratings of the capacitor selected. Note ripple current rating of ceramic capacitors may be missing
from the capacitor data sheet and you may need to contact the capacitor manufacturer for this rating.
If the system design requires a certain minimum value of input ripple voltage ΔVIN be maintained then the
following equation may be used.
CIN ≥ IO × D × (1–D) / ( fSW-CCM × ΔVIN)
(9)
If ΔVIN is 1% of VIN for a 24-V input to 3.3-V output application this equals 240 mV and fSW = 400 kHz.
CIN≥ 3 A × 3.3 V / 24 V × (1– 3.3 V / 24 V) / (400000 × 0.240 V)
≥ 3.7 μF
Additional bulk capacitance with higher ESR may be required to damp any resonant effects of the input
capacitance and parasitic inductance of the incoming supply lines.
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8.2.2.2.6 Discontinuous Conduction and Continuous Conduction Mode Selection
Operating frequency in DCM can be calculated as follows:
fSW(DCM) ≊ VO × (VIN-1) × 6.8 μH × 1.18 × 1020 × IO/ ((VIN–VO) × RON2)
(10)
In CCM, current flows through the inductor through the entire switching cycle and never falls to zero during the
OFF-time. The switching frequency remains relatively constant with load current and line voltage variations. The
CCM operating frequency can be calculated using Equation 7 above.
Following is a comparison pair of waveforms of the showing both CCM (upper) and DCM operating modes.
Figure 25. CCM and DCM Operating Modes VIN = 24 V,
VO = 3.3 V, IO = 3 A/0.4 A 2 μs/div
The approximate formula for determining the DCM/CCM boundary is as follows:
IDCB ≊ VO × (VIN– VO) / (2 × 6.8 μH × fSW(CCM) × VIN)
(11)
Following is a typical waveform showing the boundary condition.
Figure 26. Transition Mode Operation
VIN = 24 V, VO = 3.3 V, IO = 0.5 A 2 μs/div
The inductor internal to the module is 6.8 μH. This value was chosen as a good balance between low and high
input voltage applications. The main parameter affected by the inductor is the amplitude of the inductor ripple
current (ILR). ILR can be calculated with:
ILR P-P = VO × (VIN– VO) / (6.8µH × fSW × VIN)
where
•
VIN is the maximum input voltage and fSW is determined from Equation 13.
(12)
If the output current IO is determined by assuming that IO = IL, the higher and lower peak of ILR can be
determined. Be aware that the lower peak of ILR must be positive if CCM operation is required.
8.2.2.2.7 RON Resistor Selection
Many designs will begin with a desired switching frequency in mind. For that purpose the following equation can
be used.
fSW(CCM) ≊ VO / (1.3 × 10-10 × RON)
(13)
This can be rearranged as
16
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RON ≊ VO / (1.3 × 10 -10 × fSW(CCM))
(14)
The selection of RON and fSW(CCM) must be confined by limitations in the ON-time and OFF-time for the COT
Control Circuit Overview section.
The ON-time of the LMZ14203 timer is determined by the resistor RON and the input voltage VIN. It is calculated
as follows:
tON = (1.3 × 10-10 × RON) / VIN
(15)
The inverse relationship of tON and VIN gives a nearly constant switching frequency as VIN is varied. RON should
be selected such that the ON-time at maximum VIN is greater than 150 ns. The ON-timer has a limiter to ensure
a minimum of 150 ns for tON. This limits the maximum operating frequency, which is governed by the following
equation:
fSW(MAX) = VO / (VIN(MAX) × 150 ns)
(16)
This equation can be used to select RON if a certain operating frequency is desired so long as the minimum ONtime of 150 ns is observed. The limit for RON can be calculated as follows:
RON ≥ VIN(MAX) × 150 ns / (1.3 × 10 -10)
(17)
If RON calculated in Equation 14 is less than the minimum value determined in Equation 17 a lower frequency
should be selected. Alternatively, VIN(MAX) can also be limited to keep the frequency unchanged.
NOTE
The minimum OFF-time of 260 ns limits the maximum duty ratio. Larger RON (lower FSW)
should be selected in any application requiring large duty ratio.
8.2.3 Application Curves
100
3.5
95
3
OUTPUT CURRENT (A)
EFFICIENCY (%)
90
85
80
75
70
65
2.5
2
1.5
1
60
0.5
55
25°C
50
0
0.5
1
1.5
2
2.5
3
0
20
40
60
80
100
120
AMBIENT TEMPERATURE (°C)
OUTPUT CURRENT(A)
Figure 27. Efficiency VIN = 24 V VOUT = 5.0 V
Figure 28. Thermal Derating Curve
VIN = 24 V, VOUT = 5.0 V
Figure 29. Radiated Emissions (EN 55022 Class B)
From Evaluation Board
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9 Power Supply Recommendations
The LMZ14203 device is designed to operate from an input voltage supply range between 4.5 V and 42 V. This
input supply should be well regulated and able to withstand maximum input current and maintain a stable
voltage. The resistance of the input supply rail should be low enough that an input current transient does not
cause a high enough drop at the LMZ14203 supply voltage that can cause a false UVLO fault triggering and
system reset. If the input supply is located more than a few inches from the LMZ14203, additional bulk
capacitance may be required in addition to the ceramic bypass capacitors. The amount of bulk capacitance is not
critical, but a 47-μF or 100-μF electrolytic capacitor is a typical choice.
10 Layout
10.1 Layout Guidelines
PCB layout is an important part of DC-DC converter design. Poor board layout can disrupt the performance of a
DC-DC converter and surrounding circuitry by contributing to EMI, ground bounce and resistive voltage drop in
the traces. These can send erroneous signals to the DC-DC converter resulting in poor regulation or instability.
Good layout can be implemented by following a few simple design rules.
1. Minimize area of switched current loops.
From an EMI reduction standpoint, it is imperative to minimize the high di/dt paths during PCB layout. The
high current loops that do not overlap have high di/dt content that will cause observable high frequency noise
on the output pin if the input capacitor (Cin1) is placed at a distance away from the LMZ14203. Therefore
place CIN1 as close as possible to the LMZ14203 VIN and GND exposed pad. This will minimize the high
di/dt area and reduce radiated EMI. Additionally, grounding for both the input and output capacitor should
consist of a localized top side plane that connects to the GND exposed pad (EP).
2. Have a single point ground.
The ground connections for the feedback, soft-start, and enable components should be routed to the GND
pin of the device. This prevents any switched or load currents from flowing in the analog ground traces. If not
properly handled, poor grounding can result in degraded load regulation or erratic output voltage ripple
behavior. Provide the single point ground connection from pin 4 to EP.
3. Minimize trace length to the FB pin.
Both feedback resistors, RFBT and RFBB, and the feed forward capacitor CFF, should be close to the FB pin.
Since the FB node is high impedance, maintain the copper area as small as possible. The trace are from
RFBT, RFBB, and CFF should be routed away from the body of the LMZ14203 to minimize noise.
4. Make input and output bus connections as wide as possible.
This reduces any voltage drops on the input or output of the converter and maximizes efficiency. To optimize
voltage accuracy at the load, ensure that a separate feedback voltage sense trace is made to the load. Doing
so will correct for voltage drops and provide optimum output accuracy.
5. Provide adequate device heat-sinking.
Use an array of heat-sinking vias to connect the exposed pad to the ground plane on the bottom PCB layer.
If the PCB has a plurality of copper layers, these thermal vias can also be employed to make connection to
inner layer heat-spreading ground planes. For best results use a 6 × 6 via array with minimum via diameter
of 8 mils thermal vias spaced 59 mils (1.5 mm). Ensure enough copper area is used for heat-sinking to keep
the junction temperature below 125°C.
18
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10.2 Layout Example
VIN
VO
LMZ14203
VOUT
VIN
High
di/dt
Cin1
CO1
GND
Loop 2
Loop 1
Figure 30. Minimize Area of Current Loops in Buck Module
Top View
Thermal Vias
GND
GND
EPAD
1
2
3
4 5
6 7
VIN
EN
RON
SS
GND
VOUT
FB
CIN
VIN
COUT
VOUT
RON
RENT
RFBT
CSS
RENB
CFF
RFBB
GND Plane
Figure 31. PCB Layout Guide
Figure 32. EVM Board Layout - Top View
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Layout Example (continued)
Figure 33. EVM Board Layout - Bottom View
10.3 Power Dissipation and Board Thermal Requirements
For the design case of VIN = 24 V, VO = 3.3 V, IO = 3 A, TAMB(MAX) = 85°C , and TJUNCTION = 125°C, the device
must see a thermal resistance from case to ambient of:
RθCA< (TJ-MAX – TAMB(MAX)) / PIC-LOSS – RθJC
(18)
Given the typical thermal resistance from junction to case to be 1.9°C/W. Use the 85°C power dissipation curves
in the Typical Characteristics section to estimate the PIC-LOSS for the application being designed. In this
application it is 2.25 W.
RθCA < (125 – 85) / 2.25 W – 1.9 = 15.8
To reach RθCA = 15.8, the PCB is required to dissipate heat effectively. With no airflow and no external heat, a
good estimate of the required board area covered by 1 oz. copper on both the top and bottom metal layers is:
Board Area_cm2 > 500°C × cm2/W / RθCA
(19)
As a result, approximately 31.5 square cm of 1 oz copper on top and bottom layers is required for the PCB
design. The PCB copper heat sink must be connected to the exposed pad. Approximately thirty six, 8-mil thermal
vias spaced 59 mils (1.5 mm) apart must connect the top copper to the bottom copper. For an example of a high
thermal performance PCB layout, refer to the Evaluation Board application note AN-2024 SNVA422.
10.4 Power Module SMT Guidelines
The recommendations below are for a standard module surface mount assembly
• Land Pattern – Follow the PCB land pattern with either soldermask defined or non-soldermask defined pads
• Stencil Aperture
– For the exposed die attach pad (DAP), adjust the stencil for approximately 80% coverage of the PCB land
pattern
– For all other I/O pads use a 1:1 ratio between the aperture and the land pattern recommendation
• Solder Paste – Use a standard SAC Alloy such as SAC 305, type 3 or higher
• Stencil Thickness – 0.125 mm to 0.15 mm
• Reflow - Refer to solder paste supplier recommendation and optimized per board size and density
• Refer to AN SNAA214 for Reflow information.
• Maximum number of reflows allowed is one
20
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Power Module SMT Guidelines (continued)
Figure 34. Sample Reflow Profile
Table 3. Sample Reflow Profile Table
Probe
Max Temp
(°C)
Reached
Max Temp
Time Above
235°C
Reached
235°C
Time Above
245°C
Reached
245°C
Time Above
260°C
Reached
260°C
#1
242.5
6.58
0.49
6.39
#2
242.5
7.10
0.55
6.31
0.00
–
0.00
–
0.00
7.10
0.00
–
#3
241.0
7.09
0.42
6.44
0.00
–
0.00
–
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11 Device and Documentation Support
11.1 Custom Design With WEBENCH® Tools
Click here to create a custom design using the LMZ14203 device with the WEBENCH® Power Designer.
1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements.
2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial.
3. Compare the generated design with other possible solutions from Texas Instruments.
The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time
pricing and component availability.
In most cases, these actions are available:
• Run electrical simulations to see important waveforms and circuit performance
• Run thermal simulations to understand board thermal performance
• Export customized schematic and layout into popular CAD formats
• Print PDF reports for the design, and share the design with colleagues
Get more information about WEBENCH tools at www.ti.com/WEBENCH.
11.2 Device Support
11.2.1 Development Support
WEBENCH software uses an iterative design procedure and accesses comprehensive databases of
components. For more details, go to www.ti.com/webench.
11.2.2 Third-Party Products Disclaimer
TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT
CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES
OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER
ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.
11.3 Documentation Support
11.3.1 Related Documentation
This section contains additional document support.
• Design Summary LMZ1 and LMZ2 Power Modules, SNAA214
• Inverting Application for the LMZ14203 SIMPLE SWITCHER Power Module, SNVA425
• Evaluation Board Application Note AN-2024, SNVA422
• Absolute Maximum Ratings for Soldering, SNOA549
11.4 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.
11.5 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
22
Submit Documentation Feedback
Copyright © 2009–2017, Texas Instruments Incorporated
Product Folder Links: LMZ14203
LMZ14203
www.ti.com
SNVS632S – DECEMBER 2009 – REVISED JULY 2017
Community Resources (continued)
contact information for technical support.
11.6 Trademarks
E2E is a trademark of Texas Instruments.
WEBENCH is a registered trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.7 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.
11.8 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 © 2009–2017, Texas Instruments Incorporated
Product Folder Links: LMZ14203
23
PACKAGE OPTION ADDENDUM
www.ti.com
8-Jan-2019
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)
LMZ14203TZ-ADJ/NOPB
ACTIVE
TO-PMOD
NDW
7
250
RoHS & Green
CU SN
Level-3-245C-168 HR
-40 to 125
LMZ14203
TZ-ADJ
LMZ14203TZE-ADJ/NOPB
ACTIVE
TO-PMOD
NDW
7
45
RoHS & Green
CU SN
Level-3-245C-168 HR
-40 to 125
LMZ14203
TZ-ADJ
LMZ14203TZX-ADJ/NOPB
ACTIVE
TO-PMOD
NDW
7
500
RoHS & Green
CU SN
Level-3-245C-168 HR
-40 to 125
LMZ14203
TZ-ADJ
(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.
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
8-Jan-2019
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 2
PACKAGE MATERIALS INFORMATION
www.ti.com
27-May-2018
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
LMZ14203TZ-ADJ/NOPB
LMZ14203TZX-ADJ/NOP
B
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
TOPMOD
NDW
7
250
330.0
24.4
10.6
14.22
5.0
16.0
24.0
Q2
TOPMOD
NDW
7
500
330.0
24.4
10.6
14.22
5.0
16.0
24.0
Q2
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
27-May-2018
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
LMZ14203TZ-ADJ/NOPB
TO-PMOD
NDW
7
250
367.0
367.0
45.0
LMZ14203TZX-ADJ/NOPB
TO-PMOD
NDW
7
500
367.0
367.0
45.0
Pack Materials-Page 2
MECHANICAL DATA
NDW0007A
BOTTOM SIDE OF PACKAGE
TOP SIDE OF PACKAGE
TZA07A (Rev D)
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
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