Datasheet

LR3966
UNISONIC TECHNOLOGIES CO., LTD
LINEAR INTEGRATED CIRCUIT
3.0A LOW DROPOUT LINEAR
REGULATOR
1

DESCRIPTION
The LR3966 is a low-noise, low-dropout linear regulator
operated from a 2.5V to 6V input voltage and is guaranteed to
deliver 3A output current. Wide range of preset output voltage
options are available. Built-in low on-resistance transistor provides
low dropout voltage and large output current. The LR3966 is
designed and optimized for battery-powered systems to work with
low noise.
The LR3966 is developed on a CMOS process technology
which allows low quiescent current operation independent of output
load current. This CMOS process also allows the LR3966 to operate
under extremely low dropout conditions.

1
TO-263-5
TO-263
1
1
TO-252-5
SOT-223
FEATURES
* 3A Guaranteed Output Current
* Ultra Low Dropout Voltage
* Low Ground Pin Current
* Low Temperature Coefficient
* Current Limiting Protection
* Thermal Shutdown Protection
* Excellent Line/Load Transient
* SENSE Option Improves Load Regulation

ORDERING INFORMATION
Ordering Number
Lead Free
Halogen Free
LR3966G-xx-AA3-A-R
LR3966G-xx-AA3-D-R
LR3966L-xx-TQ2-A-T
LR3966G-xx-TQ2-A-T
LR3966L-xx-TQ2-A-R
LR3966G-xx-TQ2-A-R
LR3966L-xx-TQ2-D-T
LR3966G-xx-TQ2-D-T
LR3966L-xx-TQ2-D-R
LR3966G-xx-TQ2-D-R
LR3966L-xx-TN5-T
LR3966G-xx-TN5-T
LR3966L-xx-TN5-R
LR3966G-xx-TN5-R
LR3966L-xx-TQ5-T
LR3966G-xx-TQ5-T
LR3966L-xx-TQ5-R
LR3966G-xx-TQ5-R
Note: Pin Assignment: G: GND
I: V IN
O: V OUT E: EN
LR3966G-xx-AA3-A-R
Package
1
SOT-223
G
SOT-223
I
TO-263
G
TO-263
G
TO-263
I
TO-263
I
TO-252-5
E
TO-252-5
E
TO-263-5
E
TO-263-5
E
A: SENSE/ADJ
Pin Assignment
2
3
4
O
I
G O
O
I
O
I
G O
G O
I
G O
I
G O
I
G O
I
G O
5
A
A
A
A
Packing
Tape Reel
Tape Reel
Tube
Tape Reel
Tube
Tape Reel
Tube
Tape Reel
Tube
Tape Reel
(1) T: Tube, R: Tape Reel
(1)Packing Type
(2) refer to Pin Assignment
(2)Pin Assignment
(3) AA3: SOT-223, TN5: TO-252-5, TQ2: TO-263,
(3)Package Type
(3) TQ5-TO-263-5
(4)Output Voltage Code
(4) xx: refer to Marking Information
(5)Green Package
(5) L: Lead Free, G: Halogen Free and Lead Free
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Copyright © 2014 Unisonic Technologies Co., Ltd
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QW-R101-032.F
LR3966

LINEAR INTEGRATED CIRCUIT
MARKING INFORMATION
PACKAGE
VOLTAGE CODE
MARKING
Pin Code
SOT-223
Voltage Code
LR3966G
XXXXXXXX
1
Pin Code
Voltage Code
18 :1.8V
33 :3.3V
AD: ADJ
TO-263
Voltage Code
L: Lead Free
G: Halogen Free
Date Code
Lot Code
3
L: Lead Free
G: Halogen Free
Date Code
Lot Code
2 3
4 5
PIN CONFIGURATION
1
3
2
VIN GND VOUT
SOT-223

2
UTC
LR3966X
XXXXXXXXXX
1

3
2
UTC
LR3966X
XXXXXXXXXXX
1
TO-252-5
TO-263-5
Date Code
1
VIN
2
GND
TO-263
EN
VIN
GND
VOUT
3
VOUT
SENSE/ADJ
1
2
3
4
5
TO-252-5/TO-263-5
PIN DESCRIPTION
PIN NAME
EN
V IN
GND
V OUT
ADJ
SENSE
DESCRIPTION
Active-Low Shutdown Input. Connect EN to V IN for normal operation.
Power Input Voltage. Supply voltage can range from 2.5V to 6V. Bypass with a 68µF capacitor to
GND.
Ground
Output Voltage
Voltage-adjust Input. Connect an external resistive voltage-divider from V OUT to ADJ to set the
output voltage between 1.145V and 5V.
Remote sense pin.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R101-032.F
LR3966

LINEAR INTEGRATED CIRCUIT
BLOCK DIAGRAM
VIN
ON
OFF
Thermal
Sensor
Current Limit
EN
EN
VOUT
SENSE
+
1.145V
VREF
ERR AMP
-
ADJ
GND
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QW-R101-032.F
LR3966

LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATING (T A =25°С)
PARAMETER
SYMBOL
RATINGS
UNIT
Input Supply Voltage(Survival)
V IN
0~7.0
V
Enable Input Voltage(Survival)
V EN
0~7.0
V
Power Dissipation
PD
925
mW
Operation Junction Temperature
T OPR
-40 ~ +125
°С
Storage Temperature
T STG
-65 ~ +150
°С
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.

ELECTRICAL CHARACTERISTICS
Unless otherwise specified: V IN =V O(NOM ) +1V or V IN =2.5V whichever is greater, I L =10mA, C IN =68µF, C OUT =33µF,
V EN =V IN -0.3V, TJ=25°C.
PARAMETER
SYMBOL
TEST CONDITION
MIN
TYP
MAX UNITS
10mA<I L <3A
-2
2
%
Output Voltage Tolerance
V OUT
V OUT +1V<V IN <6V
10mA<I L <1.5A
Adjustable Pin Voltage
V ADJ
1.117
1.145
1.174
V
(ADJ version)
V OUT +1.5V<V IN <6V
Line Regulation (Note 1)
REGLINE V OUT +1V≤V IN ≤6V
0.08
0.18
%/V
Load Regulation (Note 1, 2)
REGLOAD 10mA≤I L ≤3A
0.25
0.55
%
I L =300mA
50
65
Dropout Voltage (Note 3)
V DROP
mV
I L =3A
480
580
I L =300mA
60
120
I GND1
µA
Ground Pin Current
I L =3A
60
120
I GND2
V EN <0.2V
0.1
5
µA
Output Peak Current
I PEAK
3.5
4.5
A
V IH
Output=High
V IN /2+0.5
V IN
Enable Threshold
V
V IL
Output=Low
0
V IN /2-0.5
Enable Input Current
I EN
V EN =V IN
0.05
2
µA
Thermal Shutdown Temperature
T SD
165
°С
Thermal Shutdown Hysteresis
DT SD
10
°С
Notes: 1. Output voltage line regulation is defined as the change in output voltage from the nominal value resulting
from a change in the input line voltage. Output voltage load regulation is defined as the change in output
voltage from the nominal value as the load current increases from no load to full load.
2. Regulation is measured at constant junction temperature by using a 20ms current pulse. Devices are
tested for load regulation in the load range from 10mA to 3.0A
3. Dropout voltage is defined as the voltage from the input to output when output is 2% below the nominal
value. Dropout voltage specification applies only to output voltages of 2.5V and above.
UNISONIC TECHNOLOGIES CO., LTD
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QW-R101-032.F
LR3966

LINEAR INTEGRATED CIRCUIT
TYPICAL APPLICATION CIRCUIT
VIN
CIN +
68µF
ON
VOUT
VIN
R2
LR3966
VOUT
ADJ
EN
OFF
+ COUT
33µF
GND
R1
VOUT=VREF(1+R2/R1)
VOUT
VIN
CIN +
68uF
ON
VOUT
VIN
LR3966
SENSE
EN
OFF
GND
+ COUT
33µF
L
O
A
D
* LR3966 can deliver a continuous current of 3.0A over the full operating temperature. However, the output current is
limited by the restriction of power dissipation which differs from packages. A heat sink may be required depending
on the maximum power dissipation and maximum ambient temperature of application. With respect to the applied
package, the maximum output current of 3.0A may be still undeliverable.
* When a Pull-Up resistor is connected between V EN terminal and V EN Signal (or V IN line), the resistance of the
Pull-Up resistor should be kept under 10kΩ.
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QW-R101-032.F
LR3966

LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS
(V IN = V OUT + 1V or V IN =2.25V whichever is greater , C IN =68µF, C OUT =33µF,T A = 25°C, unless otherwise
specified)
Temperature vs.
Output Voltage Change
3.4
Ground Pin Current vs. Input Voltage
VOUT=3.3V
250
Ground Pin Current, IGND (µA)
3.2
VOUT (V)
3.0
2.8
2.6
2.4
2.2
2.0
VOUT=1.8V
1.8
-40
-20
0
20
40
60
200
150
100
VOUT=3.3V
50
80
100 120 140
2
3
Temp (℃)
4
5
6
Input Voltage, VIN (V)
Power ON
Drop-Out Voltage vs. Load Current
480
420
Drop-Out (mV)
360
VOUT=3.3V
300
VIN
240
180
VOUT
120
60
0
0
400 800 1200 1600 2000 2400 2800 3200
Output Current, IOUT (mA)
Load Transient
VIN
VOUT
IL
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QW-R101-032.F
LR3966
LINEAR INTEGRATED CIRCUIT
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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QW-R101-032.F
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