STMicroelectronics L6932 Datasheet
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L6932
HIGH PERFORMANCE 2A ULDO LINEAR REGULATOR
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2V TO 14V INPUT VOLTAGE RANGE
200m
Ω Rdson MAX.
200 µA QUIESCENT CURRENT AT ANY LOAD
EXCELLENT LOAD AND LINE REGULATION
1.5V, 1.8V AND 2.5V FIXED VOLTAGE
ADJUSTABLE FROM 1.2V TO 5V (L6932D1.2)
1% VOLTAGE REGULATION ACCURACY
SHORT CIRCUIT PROTECTION
THERMAL SHUT DOWN
SO-8 (4+4) PACKAGE
SO-8 (4+4)
ORDERING NUMBERS:
L6932D1.2 (SO-8) L6932D1.2TR (T&R)
L6932D1.5 (SO-8) L6932D1.5TR (T&R)
L6932D1.8 (SO-8) L6932D1.8TR (T&R)
L6932D2.5 (SO-8) L6932D2.5TR (T&R)
APPLICATIONS
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MOTHERBOARDS
MOBILE PC
HAND-HELD INSTRUMENTS
PCMCIA CARDS
PROCESSORS I/O
CHIPSET AND RAM SUPPLY
DESCRIPTION
The L6932 Ultra Low Drop Output linear regulator operates from 2V to 14V and is able to support 2A.
Designed with an internal 50m Ω N-channel
TYPICAL OPERATING CIRCUIT
V
IN
2V to 14V
IN
2
L6932D
C1
Mosfet, can be usefull for the DC-DC conversion between 2.5V and 1.5V at 2A in portable applications reducing the power dissipation.
L6932 is available in 1.5V, 1.8V, 2.5V and adj version from 1.2V and ensure a voltage regulation accuracy of 1%.
The current limit is fixed at 2.5A to control the current in short circuit condition within ±8%. The current is sensed in the power mos in order to limit the power dissipation.
The device is also provided of a thermal shut down that limits the internal temperature at 150°C with an histeresys of 20°C. L6932 provides the Enable and the Power good functions.
3
OUT
4
PGOOD C2
V
OUT
1.5V-1.8V-2.5V
1 5,6,7,8
GND
EN
V
IN
2V to 14V
C1
IN
2 4
OUT
L6932D
5,6,7,8
GND
1
EN
3
ADJ
R1
R2
C2
V
OUT
1.2V to 5V
December 2005
Rev. 9
1/11
L6932
PIN CONNECTIONS
EN
IN
ADJ
OUT
3
4
1
2
L6932D1.2
6
5
8
7
GND
GND
GND
GND
EN
IN
OUT
PGOOD
1
2
3
4
L6932D1.5
L6932D1.8
L6932D2.5
8
7
6
5
GND
GND
GND
GND
PIN FUNCTION
N°
1
2
L6232D
1.2
EN
IN
L6232D
1.5/1.8/
2.5
ADJ –
Description
Enables the device if connected to Vin and disables the device if forced to gnd.
Supply voltage. This pin is connected to the drain of the internal N-mos. Connect this pin to a capacitor larger than 10
µF.
Connecting this pin to a voltage divider it is possible to programme the output voltage between 1.2V and 5V.
3
4
5, 6, 7, 8
–
OUT
–
OUT Regulated output voltage. This pin is connected to the source of the internal N-mos.
Connect this pin to a capacitor of 10
µF.
– Regulated output voltage. This pin is connected to the source of the internal N-mos.
Connect this pin to a capacitor of 10
µF.
PGOOD Power good output. The pin is open drain and detects the output voltage. It is forced low if the output voltage is lower than 90% of the programmed voltage.
GND Ground pin.
ABSOLUTE MAXIMUM RATINGS
Symbol
V in
VIN and Pgood
EN, OUT and ADJ
Parameter Value
14.5
-0.3 to (V in
+0.3)
Unit
V
V
THERMAL DATA
Symbol Parameter
R th J-amb
T max
Thermal Resistance Junction to Ambient
Maximum Junction Temperature
T stg
Storage Temperature Range
(*) Measured on Demoboard with about 4 cm
2
of dissipating area 2 Oz.
Value
62 (*)
150
-65 to 150
Unit
°C/W
°C
°C
2/11
L6932
BLOCK DIAGRAM (Referred to the Fixed Voltage version)
IN
REFERENCE
VREF=1.25V
VREF
+
-
ERROR
AMPL.
CHARGE
PUMP
DRIVER
CURRENT
LIMIT
OUT
EN ENABLE
THERMAL
SENSOR
PG
0.9 VREF
-
+
GND
D99IN1100
ELECTRICAL CHARACTERISTCS (T j
= 25°C, V
IN
= 5V unless otherwise specified)
(*) Specification referred to T j
from -25°C to 125°C.
Symbol Parameter Test Condition Min. Typ.
V in
V o
Operating Supply Voltage
Output voltage L6932D1.2
2
1.188
1.2
Output voltage L6932D1.5
Output voltage L6932D1.8
Output voltage L6932D2.5
L6932D1.2
Line Regulation
L6932D1.5
Line Regulation
L6932D1.8
Line Regulation
L6932D2.5
Line Regulation
L6932D1.2 Load Regulation
L6932D1.5 Load Regulation
L6932D1.8 Load Regulation
L6932D2.5 Load Regulation
I o
= 0.1A; V in
= 3.3V
I o
= 0.1A; V in
= 3.3V
I o
= 0.1A; V in
= 3.3V
I o
= 0.1A; V in
= 3.3V
V in
= 2.5V ±10%; I o
= 10mA
V in
= 3.3V ±10%; I o
= 10mA
V in
= 5V ±10%; I o
= 10mA
V in
= 2.5V ±10%; I o
= 10mA
V in
= 3.3V ±10%; I o
= 10mA
V in
= 5V ±10%; I o
= 10mA
V in
= 2.5V ±10%; I o
= 10mA
V in
= 3.3V ±10%; I o
= 10mA
V in
= 5V ±10%; I o
= 10mA
V in
= 3.3V ±10%; I o
= 10mA
V in
= 5V ±10%; I o
= 10mA
V in
= 3.3V; 0.1A < I o
< 2A
V in
= 3.3V; 0.1A < I o
< 2A
V in
= 3.3V; 0.1A < I o
< 2A
V in
= 3.3V; 0.1A < I o
< 2A
1.485
1.782
2.475
1.5
1.8
2.5
R dson
Drain Source ON resistance
5
5
5
5
5
5
15
15
15
15
200
5
5
5
5
5
Max.
14
1.212
1.515
1.818
2.525
mV mV mV mV mV
Unit
V
V
V
V
V mV mV mV mV mV mV mV mV mV mV m
Ω
3/11
L6932
ELECTRICAL CHARACTERISTCS (continued)
Symbol
I occ
I q
I sh
Parameter
Current limiting
Quiescent current
Shutdown current
Ripple Rejection
Test Condition
2V < V in
< 14V f = 120Hz, I o
= 1A
V in
= 5V,
∆V in
= 2Vpp
V en
EN Input Threshold
Pgood threshold
Pgood Hysteresis
Pgood saturation
V o
rise
I pgood
=1mA
*
Min. Typ.
2.3
2.5
0.2
60
0.5
75
0.65
90
10
0.2
Max.
2.7
0.4
25
0.8
0.4
Unit
A mA
µA dB
V
%Vo
%Vo
V
Figure 1. Output Voltage vs. Junction
Temperature (L6932D1.2)
1.213
1.212
1.212
V
1.211
1.211
1.210
1.210
1.209
-60 -40 -20 0 20 40 60 80 100 120 140 160
Temp [°C]
Figure 2. Output Voltage vs. Junction
Temperature (L6932D1.8)
1.808
1.804
1.800
V
1.796
1.792
1.788
-60 -40 -20 0 20 40 60 80 100 120 140 160
Temp [°C]
Figure 3. Output Voltage vs. Junction
Temperature (L6932D2.5)
2.520
2.515
2.510
V
2.505
2.500
2.495
-60 -40 -20 0 20 40 60 80 100 120 140 160
Temp [°C]
Figure 4. Quiescent Current vs. Junction
Temperature
310
300
290
Iq
280
(uA)
270
Vin=5V
260
250
-40 -20 0 20 40 60
Temp [°C ]
80 100 120 140
4/11
Figure 5. Shutdown Current vs. Junction TemperatureAPPLICATION INFORMATIONS
7.5
7
6.5
Ishdn 6
(uA)
5.5
5
4.5
4
-40
Vin=5V
-20 0 20 40
Temp [°C ]
60 80 100 120 140
APPLICATION CIRCUIT
In figure 6 the schematic circuit of the demoboards are shown.
Figure 6. Demoboards Schematic Circuit
V
IN
IN
2
C1
EN
1
5
L6932D1.5
L6932D1.8
L6932D2.5
6 7
GND
3
OUT
8
4
PGOOD C2
V
OUT
L6932
V
IN
IN
2
C1
EN
1
L6932D1.2
5
GND
6 7
4
OUT
8
3
ADJ
R1
R2
C2
V
OUT
1.2V to 5V
V
OUT
=
1.2
R2
× (R1 + R2)
COMPONENT LIST
Fixed version
Reference
C1
C2
Part Number
C34Y5U1E106Z
C34Y5U1E106Z
Description
10uF, 25V
10uF, 25V
Manufacturer
TOKIN
TOKIN
5/11
L6932
Figure 7. Demoboard Layout (Fixed Version)
Adjustable version
Reference
C1
C2
R1
R2
Part Number
C34Y5U1E106Z
C34Y5U1E106Z
Description
10uF, 25V
10uF, 25V
5.6K, 1%, 0.25W
3.3K, 1%, 0.25W
Figure 8. Demoboard Layout (Adjustable Version)
Manufacturer
TOKIN
TOKIN
Neohm
Neohm
COMPONENTS SELECTION
Input Capacitor
The input capacitor value depends on a lot of factors such as load transient requirements, input source (battery or DC/DC converter) and its distance from the input cap. Usually a 47 µF is enough for any application but a much lower value can be sufficient in many cases.
Output Capacitor
The output capacitor choice depends basically on the load transient requirements.
Tantalum, Speciality Polimer, POSCAP and aluminum capacitors are good and offer very low ESR values.
6/11
L6932
Multilayer ceramic caps have the lowest ESR and can be required for particular applications. Nevertheless in several applications they are ok, the loop stability issue has to be considered (see loop stability section).
Below a list of some suggested capacitor manufacturers.
Manufacturer Type Cap Value (
µF)
Rated Voltage (V)
PANASONIC CERAMIC 1 to 47 4 to 16
TAYO YUDEN
TDK
CERAMIC
CERAMIC
1 to 47
1 to 47
4 to 16
4 to 16
TOKIN
SANYO
PANASONIC
KEMET
CERAMIC
POSCAP
SP
TANTALUM
1 to 47
1 to 47
1 to 47
1 to 47
Loop Stability
The stability of the loop is affected by the zero introduced by the output capacitor.
The time constant of the zero is given by:
4 to 16
4 to 16
4 to 16
4 to 16
T = ESR C
O UT
F
ZERO
=
2
⋅
This zero helps to increase the phase margin of the loop until the time constant is higher than some hundreds of nsec, depending also on the output voltage and current.
So, using very low ESR ceramic capacitors could produce oscillations at the output, in particular when regulating high output voltages (adjustable version).
To solve this issue is sufficient to add a small capacitor (e.g. 1nF to 10nF) in parallel to the high side resistor of the external divider, as shown in figure 9.
Figure 9. Compensation Network
OUT
VIN=2V TO 14V VOUT=1.2V TO 5V UP to 2A
C1
IN
2
EN
L6932D1.2
1
5
GND
6 7
4
OUT
8
3
R1
ADJ
R2
C3
C2
Thermal Considerations
Since the device is housed in a small SO(4+2+2) package the thermal issue can be the bottleneck of many applications. The power dissipated by the device is given by:
P
DISS
= (V
IN
- V
OUT
) · I
OUT
7/11
L6932
The thermal resistance junction to ambient of the demoboard is approximately 62°C/W. This mean that, considering an ambient temperature of 60°C and a maximum junction temperature of 150°C, the maximum power that the device can handle is 1.5W.
This means that the device is able to deliver a DC output current of 2A only with a very low dropout.
In many applications, high output current pulses are required. If their duration is shorter than the thermal constant time of the board, the thermal impedance (not the thermal resistance) has to be considered.
In figure 10 the thermal impedance versus the duration of the current pulse for the SO(4+2+2) mounted on board is shown.
Figure 10. Thermal Impedance
Considering a pulse duration of 1sec, the thermal impedance is close to 20°C/W, allowing much bigger power dissipated.
Example:
Vin = 3.3V
Vout = 1.8V
Iout = 2A
Pulse Duration = 1sec
The power dissipated by the device is:
P
DISS
= (V
IN
- V
OUT
) · I
OUT
= 1.5 · 2 3W
Considering a thermal impedance of 20°C/W, the maximum junction temperature will be:
T
J
= T
A
+ Z
THJA
· P
DISS
= 60 + 60 = 120°C
Obviously, with pulse durations longer than approximately 10sec the thermal impedance is very close to the thermal resistance (60°C/W to 70°C/W).
8/11
Figure 11. SO-8 Mechanical Data & Package Dimensions
DIM.
A
A1
A2
B
C
D
(1)
E mm inch
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
1.35
1.75
0.053
0.069
0.10
1.10
0.33
0.19
4.80
0.25
1.65
0.51
0.25
5.00
0.004
0.043
0.013
0.007
0.189
3.80
4.00
0.15
0.157
h
L e
H 5.80
0.25
0.40
1.27
6.20
0.228
0.50
0.010
1.27
0.016
0.050
0.244
0.020
0.050
k ddd
0˚ (min.), 8˚ (max.)
0.10
0.004
Note: (1) Dimensions D does not include mold flash, protrusions or gate burrs.
Mold flash, potrusions or gate burrs shall not exceed
0.15mm (.006inch) in total (both side).
0.010
0.065
0.020
0.010
0.197
OUTLINE AND
MECHANICAL DATA
SO-8
L6932
0016023 C
9/11
L6932
Table 1. Revision History
Date Revision
February 2003
December 2005
8
9
Description of Changes
First Issue
Added new Ordering Numbers: L6932D1.5 & L6932D1.5TR.
10/11
L6932
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics.
All other names are the property of their respective owners
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