LT1963A Series

1.5A, Low Noise,

Fast Transient Response
LDO Regulators
FEATURES DESCRIPTION
n Optimized for Fast Transient Response The LT ®1963A series are low dropout regulators optimized
n Output Current: 1.5A for fast transient response. The devices are capable of
n Dropout Voltage: 340mV supplying 1.5A of output current with a dropout voltage of
n Low Noise: 40µVRMS (10Hz to 100kHz) 340mV. Operating quiescent current is 1mA, dropping to
n 1mA Quiescent Current < 1µA in shutdown. Quiescent current is well controlled; it
n No Protection Diodes Needed does not rise in dropout as it does with many other regula-
n Controlled Quiescent Current in Dropout tors. In addition to fast transient response, the LT1963A
n Fixed Output Voltages: 1.5V, 1.8V, 2.5V, 3.3V regulators have very low output noise which makes them
n Adjustable Output from 1.21V to 20V ideal for sensitive RF supply applications.
n < 1µA Quiescent Current in Shutdown Output voltage range is from 1.21V to 20V. The LT1963A
n Stable with 10µF Output Capacitor* regulators are stable with output capacitors as low as
n Stable with Ceramic Capacitors* 10µF. Internal protection circuitry includes reverse bat-
n Reverse Battery Protection tery protection, current limiting, thermal limiting and
n No Reverse Current reverse current protection. The devices are available in
n Thermal Limiting fixed output voltages of 1.5V, 1.8V, 2.5V, 3.3V and as
n 5-Lead TO-220, DD, 3-Lead SOT-223 and an adjustable device with a 1.21V reference voltage. The
8-Lead SO Packages LT1963A regulators are available in 5-lead TO-220, DD,
n AEC-Q100 Qualified for Automotive Applications 3‑lead SOT-223, 8-lead SO and 16-lead TSSOP packages.
All registered trademarks and trademarks are the property of their respective owners. Protected
APPLICATIONS by U.S. patents, including 6118263, 6144250.
*See Applications Information Section.
n 3.3V to 2.5V Logic Power Supplies
n Post Regulator for Switching Supplies

TYPICAL APPLICATION
Dropout Voltage
3.3V to 2.5V Regulator 400

350
2.5V
DROPOUT VOLTAGE (mV)

IN OUT 300
+ + 1.5A
VIN > 3V 10µF* 10µF*
LT1963A-2.5 250

SHDN SENSE 200

*TANTALUM,
GND 150
CERAMIC OR
ALUMINUM ELECTROLYTIC
1963A TA01 100

50

0
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
OUTPUT CURRENT (A)
1963A TA02
Rev. G

Document Feedback For more information www.analog.com 1

LT1963A Series
ABSOLUTE MAXIMUM RATINGS
(Note 1)
IN Pin Voltage......................................................... ± 20V Operating Junction Temperature Range (Note 3)
OUT Pin Voltage.......................................................±20V LT1963AE............................................– 40°C to 125°C
Input to Output Differential Voltage (Note 2)............±20V LT1963AI............................................– 40°C to 125°C
SENSE Pin Voltage ................................................ ± 20V LT1963AMP........................................– 55°C to 125°C
ADJ Pin Voltage ....................................................... ±7V Storage Temperature Range....................– 65°C to 150°C
SHDN Pin Voltage .................................................. ±20V Lead Temperature (Soldering, 10 sec)................... 300°C
Output Short-Circuit Duration ......................... Indefinite

PIN CONFIGURATION
TOP VIEW

GND 1 16 GND

FRONT VIEW FRONT VIEW NC 2 15 NC

SENSE/ OUT 3 14 IN
5 SENSE/ADJ* 5 ADJ*
4 OUT 4 OUT 4 13 IN
OUT 17
TAB IS OUT 5 12 IN
3 GND 3 GND
GND
2 IN 2 IN SENSE/ADJ* 6 11 NC
1 SHDN 1 SHDN GND 7 10 SHDN

Q PACKAGE TAB IS T PACKAGE GND 8 9 GND

5-LEAD PLASTIC DD GND 5-LEAD PLASTIC TO-220
*PIN 5 = SENSE FOR LT1963A-1.5/LT1963A-1.8/ *PIN 5 = SENSE FOR LT1963A-1.5/LT1963A-1.8/ FE PACKAGE
LT1963A-2.5/LT1963A-3.3 LT1963A-2.5/LT1963A-3.3 16-LEAD PLASTIC TSSOP
= ADJ FOR LT1963A = ADJ FOR LT1963A EXPOSED PAD (PIN 17) IS GND. MUST BE
TJMAX = 125°C, θJA = 30°C/W TJMAX = 125°C, θJA = 50°C/W SOLDERED TO THE PCB.
*PIN 6 = SENSE FOR LT1963A-1.5/LT1963A-1.8/
LT1963A-2.5/LT1963A-3.3
= ADJ FOR LT1963A
TJMAX = 125°C, θJA = 38°C/W

TOP VIEW
FRONT VIEW
OUT 1 8 IN
3 OUT
SENSE/ADJ* 2 7 GND
TAB IS
GND 2 GND GND 3 6 GND
NC 4 5 SHDN
1 IN
S8 PACKAGE
ST PACKAGE 8-LEAD PLASTIC SO
3-LEAD PLASTIC SOT-223 *PIN 2 = SENSE FOR LT1963A-1.5/LT1963A-1.8/
TJMAX = 125°C, θJA = 50°C/W LT1963A-2.5/LT1963A-3.3
= ADJ FOR LT1963A
TJMAX = 125°C, θJA = 70°C/W

Rev. G

2 For more information www.analog.com

 LT1963A Series
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1963AEQ#PBF LT1963AEQ#TRPBF LT1963AEQ 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AIQ#PBF LT1963AIQ#TRPBF LT1963AIQ 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AMPQ#PBF LT1963AMPQ#TRPBF LT1963AMPQ 5-Lead Plastic DD-Pak –55°C to 125°C
LT1963AEQ-1.5#PBF LT1963AEQ-1.5#TRPBF LT1963AEQ-1.5 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AEQ-1.8#PBF LT1963AEQ-1.8#TRPBF LT1963AEQ-1.8 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AEQ-2.5#PBF LT1963AEQ-2.5#TRPBF LT1963AEQ-2.5 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AEQ-3.3#PBF LT1963AEQ-3.3#TRPBF LT1963AEQ-3.3 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AET#PBF LT1963AET#TRPBF LT1963AET 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AIT#PBF LT1963AIT#TRPBF LT1963AIT 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AET-1.5#PBF LT1963AET-1.5#TRPBF LT1963AET-1.5 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AET-1.8#PBF LT1963AET-1.8#TRPBF LT1963AET-1.8 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AET-2.5#PBF LT1963AET-2.5#TRPBF LT1963AET-2.5 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AET-3.3#PBF LT1963AET-3.3#TRPBF LT1963AET-3.3 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AEFE#PBF LT1963AEFE#TRPBF 1963AEFE 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AIFE#PBF LT1963AIFE#TRPBF 1963AIFE 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-1.5#PBF LT1963AEFE-1.5#TRPBF 1963AEFE15 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-1.8#PBF LT1963AEFE-1.8#TRPBF 1963AEFE18 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-2.5#PBF LT1963AEFE-2.5#TRPBF 1963AEFE25 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-3.3#PBF LT1963AEFE-3.3#TRPBF 1963AEFE33 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEST-1.5#PBF LT1963AEST-1.5#TRPBF 963A15 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-1.8#PBF LT1963AEST-1.8#TRPBF 963A18 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-2.5#PBF LT1963AEST-2.5#TRPBF 963A25 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-3.3#PBF LT1963AEST-3.3#TRPBF 963A33 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AES8#PBF LT1963AES8#TRPBF 1963A 8-Lead Plastic SO –40°C to 125°C
LT1963AIS8#PBF LT1963AIS8#TRPBF 1963A 8-Lead Plastic SO –40°C to 125°C
LT1963AMPS8#PBF LT1963AMPS8#TRPBF 963AMP 8-Lead Plastic SO –55°C to 125°C
LT1963AES8-1.5#PBF LT1963AES8-1.5#TRPBF 963A15 8-Lead Plastic SO –40°C to 125°C
LT1963AES8-1.8#PBF LT1963AES8-1.8#TRPBF 963A18 8-Lead Plastic SO –40°C to 125°C
LT1963AES8-2.5#PBF LT1963AES8-2.5#TRPBF 963A25 8-Lead Plastic SO –40°C to 125°C
LT1963AES8-3.3#PBF LT1963AES8-3.3#TRPBF 963A33 8-Lead Plastic SO –40°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1963AEQ LT1963AEQ#TR LT1963AEQ 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AIQ LT1963AIQ#TR LT1963AIQ 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AMPQ LT1963AMPQ#TR LT1963AMPQ 5-Lead Plastic DD-Pak –55°C to 125°C
LT1963AEQ-1.5 LT1963AEQ-1.5#TR LT1963AEQ-1.5 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AEQ-1.8 LT1963AEQ-1.8#TR LT1963AEQ-1.8 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AEQ-2.5 LT1963AEQ-2.5#TR LT1963AEQ-2.5 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AEQ-3.3 LT1963AEQ-3.3#TR LT1963AEQ-3.3 5-Lead Plastic DD-Pak –40°C to 125°C
LT1963AET LT1963AET#TR LT1963AET 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AIT LT1963AIT#TR LT1963AIT 5-Lead Plastic TO-220 –40°C to 125°C
Rev. G

For more information www.analog.com 3

LT1963A Series
ORDER INFORMATION
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1963AET-1.5 LT1963AET-1.5#TR LT1963AET-1.5 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AET-1.8 LT1963AET-1.8#TR LT1963AET-1.8 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AET-2.5 LT1963AET-2.5#TR LT1963AET-2.5 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AET-3.3 LT1963AET-3.3#TR LT1963AET-3.3 5-Lead Plastic TO-220 –40°C to 125°C
LT1963AEFE LT1963AEFE#TR 1963AEFE 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AIFE LT1963AIFE#TR 1963AIFE 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-1.5 LT1963AEFE-1.5#TR 1963AEFE15 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-1.8 LT1963AEFE-1.8#TR 1963AEFE18 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-2.5 LT1963AEFE-2.5#TR 1963AEFE25 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEFE-3.3 LT1963AEFE-3.3#TR 1963AEFE33 16-Lead Plastic TSSOP –40°C to 125°C
LT1963AEST-1.5 LT1963AEST-1.5#TR 963A15 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-1.8 LT1963AEST-1.8#TR 963A18 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-2.5 LT1963AEST-2.5#TR 963A25 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-3.3 LT1963AEST-3.3#TR 963A33 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AES8 LT1963AES8#TR 1963A 8-Lead Plastic SO –40°C to 125°C
LT1963AIS8 LT1963AIS8#TR 1963A 8-Lead Plastic SO –40°C to 125°C
LT1963AMPS8 LT1963AMPS8#TR 963AMP 8-Lead Plastic SO –55°C to 125°C
LT1963AES8-1.5 LT1963AES8-1.5#TR 963A15 8-Lead Plastic SO –40°C to 125°C
LT1963AES8-1.8 LT1963AES8-1.8#TR 963A18 8-Lead Plastic SO –40°C to 125°C
LT1963AES8-2.5 LT1963AES8-2.5#TR 963A25 8-Lead Plastic SO –40°C to 125°C
LT1963AES8-3.3 LT1963AES8-3.3#TR 963A33 8-Lead Plastic SO –40°C to 125°C
AUTOMOTIVE PRODUCTS**
LT1963AEST-1.5#WPBF LT1963AEST-1.5#WTRPBF 963A15 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-1.8#WPBF LT1963AEST-1.8#WTRPBF 963A18 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-2.5#WPBF LT1963AEST-2.5#WTRPBF 963A25 3-Lead Plastic SOT-223 –40°C to 125°C
LT1963AEST-3.3#WPBF LT1963AEST-3.3#WTRPBF 963A33 3-Lead Plastic SOT-223 –40°C to 125°C
Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
**Versions of this part are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. These
models are designated with a #W suffix. Only the automotive grade products shown are available for use in automotive applications. Contact your
local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for
these models.

Rev. G

4 For more information www.analog.com

 LT1963A Series
ELECTRICAL CHARACTERISTICS
The l denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 3)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage (Notes 4,12) ILOAD = 0.5A 1.9 V
ILOAD = 1.5A l 2.1 2.5 V
Regulated Output Voltage (Note 5) LT1963A-1.5 VIN = 2.21V, ILOAD = 1mA 1.477 1.500 1.523 V
2.5V < VIN < 20V, 1mA < ILOAD < 1.5A l 1.447 1.500 1.545 V
LT1963A-1.8 VIN = 2.3V, ILOAD = 1mA 1.773 1.800 1.827 V
2.8V < VIN < 20V, 1mA < ILOAD < 1.5A l 1.737 1.800 1.854 V
LT1963A-2.5 VIN = 3V, ILOAD = 1mA 2.462 2.500 2.538 V
3.5V < VIN < 20V, 1mA < ILOAD < 1.5A l 2.412 2.500 2.575 V
LT1963A-3.3 VIN = 3.8V, ILOAD = 1mA 3.250 3.300 3.350 V
4.3V < VIN < 20V, 1mA < ILOAD < 1.5A l 3.200 3.300 3.400 V
ADJ Pin Voltage (Notes 4, 5) LT1963A VIN = 2.21V, ILOAD = 1mA 1.192 1.210 1.228 V
2.5V < VIN < 20V, 1mA < ILOAD < 1.5A l 1.174 1.210 1.246 V
Line Regulation LT1963A-1.5 ∆VIN = 2.21V to 20V, ILOAD = 1mA l 2.0 6 mV
LT1963A-1.8 ∆VIN = 2.3V to 20V, ILOAD = 1mA l 2.5 7 mV
LT1963A-2.5 ∆VIN = 3V to 20V, ILOAD = 1mA l 3.0 10 mV
LT1963A-3.3 ∆VIN = 3.8V to 20V, ILOAD = 1mA l 3.5 10 mV
LT1963A (Note 4) ∆VIN = 2.21V to 20V, ILOAD = 1mA l 1.5 5 mV
Load Regulation LT1963A-1.5 VIN = 2.5V, ∆ILOAD = 1mA to 1.5A 2 9 mV
VIN = 2.5V, ∆ILOAD = 1mA to 1.5A l 18 mV
LT1963A-1.8 VIN = 2.8V, ∆ILOAD = 1mA to 1.5A 2 10 mV
VIN = 2.8V, ∆ILOAD = 1mA to 1.5A l 20 mV
LT1963A-2.5 VIN = 3.5V, ∆ILOAD = 1mA to 1.5A 2.5 15 mV
VIN = 3.5V, ∆ILOAD = 1mA to 1.5A l 30 mV
LT1963A-3.3 VIN = 4.3V, ∆ILOAD = 1mA to 1.5A 3 20 mV
VIN = 4.3V, ∆ILOAD = 1mA to 1.5A l 35 mV
LT1963A (Note 4) VIN = 2.5V, ∆ILOAD = 1mA to 1.5A 2 8 mV
VIN = 2.5V, ∆ILOAD = 1mA to 1.5A l 15 mV
Dropout Voltage ILOAD = 1mA 0.02 0.06 V
VIN = VOUT(NOMINAL) ILOAD = 1mA l 0.10 V
(Notes 6, 7, 12) ILOAD = 100mA 0.10 0.17 V
ILOAD = 100mA l 0.22 V
ILOAD = 500mA 0.19 0.27 V
ILOAD = 500mA l 0.35 V
ILOAD = 1.5A 0.34 0.45 V
ILOAD = 1.5A l 0.55 V
GND Pin Current ILOAD = 0mA l 1.0 1.5 mA
VIN = VOUT(NOMINAL) + 1V ILOAD = 1mA l 1.1 1.6 mA
(Notes 6, 8) ILOAD = 100mA l 3.8 5.5 mA
ILOAD = 500mA l 15 25 mA
ILOAD = 1.5A l 80 120 mA
Output Voltage Noise COUT = 10µF, ILOAD = 1.5A, BW = 10Hz to 100kHz 40 µVRMS
ADJ Pin Bias Current (Notes 4, 9) 3 10 µA
Shutdown Threshold VOUT = Off to On l 0.90 2 V
VOUT = On to Off l 0.25 0.75 V
SHDN Pin Current (Note 10) VSHDN = 0V 0.01 1 µA
VSHDN = 20V 3 30 µA
Quiescent Current in Shutdown VIN = 6V, VSHDN = 0V 0.01 1 µA

Rev. G

For more information www.analog.com 5

LT1963A Series
ELECTRICAL CHARACTERISTICS
The l denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 3)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Ripple Rejection VIN – VOUT = 1.5V (Avg), VRIPPLE = 0.5VP-P, 55 63 dB
fRIPPLE = 120Hz, ILOAD = 0.75A
Current Limit VIN = 7V, VOUT = 0V 2 A
VIN = VOUT(NOMINAL) + 1V, ∆VOUT = – 0.1V l 1.6 A
Input Reverse Leakage Current (Note 13) Q, T, S8 Packages VIN = –20V, VOUT = 0 l 1 mA
ST Package VIN = –20V, VOUT = 0 l 2 mA
Reverse Output Current (Note 11) LT1963A-1.5 VOUT = 1.5V, VIN < 1.5V 600 1200 µA
LT1963A-1.8 VOUT = 1.8V, VIN < 1.8V 600 1200 µA
LT1963A-2.5 VOUT = 2.5V, VIN < 2.5V 600 1200 µA
LT1963A-3.3 VOUT = 3.3V, VIN < 3.3V 600 1200 µA
LT1963A (Note 4) VOUT = 1.21V, VIN < 1.21V 300 600 µA

Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 6: To satisfy requirements for minimum input voltage, the LT1963A
may cause permanent damage to the device. Exposure to any Absolute (adjustable version) is tested and specified for these conditions with an
Maximum Rating condition for extended periods may affect device external resistor divider (two 4.12k resistors) for an output voltage of 2.4V.
reliability and lifetime. The external resistor divider will add a 300µA DC load on the output.
Note 2: Absolute maximum input to output differential voltage can not Note 7: Dropout voltage is the minimum input to output voltage differential
be achieved with all combinations of rated IN pin and OUT pin voltages. needed to maintain regulation at a specified output current. In dropout, the
With the IN pin at 20V, the OUT pin may not be pulled below 0V. The total output voltage will be equal to: VIN – VDROPOUT.
measured voltage from IN to OUT can not exceed ± 20V. Note 8: GND pin current is tested with VIN = VOUT(NOMINAL) + 1V and a
Note 3: The LT1963A regulators are tested and specified under pulse load current source load. The GND pin current will decrease at higher input
conditions such that TJ ≈ TA. The LT1963AE is 100% tested at TA = 25°C. voltages.
Performance at –40°C and 125°C is assured by design, characterization and Note 9: ADJ pin bias current flows into the ADJ pin.
correlation with statistical process controls. The LT1963AI is guaranteed Note 10: SHDN pin current flows into the SHDN pin.
over the full –40°C to 125°C operating junction temperature range. The Note 11: Reverse output current is tested with the IN pin grounded and the
LT1963AMP is 100% tested and guaranteed over the –55°C to 125°C OUT pin forced to the rated output voltage. This current flows into the OUT
operating junction temperature range. pin and out the GND pin.
Note 4: The LT1963A (adjustable version) is tested and specified for these Note 12: For the LT1963A, LT1963A-1.5 and LT1963A-1.8 dropout voltage
conditions with the ADJ pin connected to the OUT pin. will be limited by the minimum input voltage specification under some
Note 5: Operating conditions are limited by maximum junction output voltage/load conditions.
temperature. The regulated output voltage specification will not apply Note 13: For the ST package, the input reverse leakage current increases
for all possible combinations of input voltage and output current. When due to the additional reverse leakage current for the SHDN pin, which is
operating at maximum input voltage, the output current range must be tied internally to the IN pin.
limited. When operating at maximum output current, the input voltage
range must be limited.

Rev. G

6 For more information www.analog.com

 LT1963A Series
TYPICAL PERFORMANCE CHARACTERISTICS

Typical Dropout Voltage Guaranteed Dropout Voltage Dropout Voltage

500 600 500
= TEST POINTS
450

GUARANTEED DROPOUT VOLTAGE (mV)

450
400 500
400
TJ ≤ 125°C

DROPOUT VOLTAGE (mV)

DROPOUT VOLTAGE (mV)

350 TJ = 125°C 350

400 IL = 1.5A
300 TJ ≤ 25°C 300
250 300 250
200 TJ = 25°C 200 IL = 0.5A

150 200
150
100 100 IL = 100mA
100
50 50 IL = 1mA
0 0 0
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 –50 –25 0 25 50 75 100 125
OUTPUT CURRENT (A) OUTPUT CURRENT (A) TEMPERATURE (°C)
1963A G01 1963A G02 1963A G03

Quiescent Current LT1963A-1.5 Output Voltage LT1963A-1.8 Output Voltage

1.4 1.54 1.84
IL = 1mA IL = 1mA
1.2 1.53 1.83
LT1963A-1.5/1.8/-2.5/-3.3
QUIESCENT CURRENT (mA)

1.52 1.82
1.0
OUTPUT VOLTAGE (V)

1.51 OUTPUT VOLTAGE (V) 1.81

0.8 LT1963A
1.50 1.80
0.6
1.49 1.79
0.4
1.48 1.78
VIN = 6V
0.2 RL = ∞, IL = 0 1.47 1.77
VSHDN = VIN
0 1.46 1.76
–50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125
TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C)
1963A G04 1963A G40 1963A G05

LT1963A-2.5 Output Voltage LT1963A-3.3 Output Voltage LT1963A ADJ Pin Voltage
2.58 3.38 1.230
IL = 1mA IL = 1mA IL = 1mA
2.56 3.36 1.225

2.54 3.34 1.220

OUTPUT VOLTAGE (V)

OUTPUT VOLTAGE (V)

ADJ PIN VOLTAGE (V)

2.52 3.32 1.215

2.50 3.30 1.210

2.48 3.28 1.205

2.46 3.26 1.200

2.44 3.24 1.195

2.42 3.22 1.190

–50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125
TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C)
1963A G06 1963A G07 1963A G08

Rev. G

For more information www.analog.com 7

 LT1963A Series
TYPICAL PERFORMANCE CHARACTERISTICS

LT1963A-1.5 Quiescent Current LT1963A-1.8 Quiescent Current LT1963A-2.5 Quiescent Current

14 14 14
TJ = 25°C TJ = 25°C TJ = 25°C
R =∞ RL = ∞ RL = ∞
12 L 12 12
VSHDN = VIN VSHDN = VIN VSHDN = VIN
QUIESCENT CURRENT (mA)

QUIESCENT CURRENT (mA)

QUIESCENT CURRENT (mA)

10 10 10

8 8 8

6 6 6

4 4 4

2 2 2

0 0 0
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10
INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V)
1963A G41 1963A G09 1963A G10

LT1963A-3.3 Quiescent Current LT1963A Quiescent Current LT1963A-1.5 GND Pin Current
14 1.4 25
TJ = 25°C TJ = 25°C TJ = 25°C
RL = ∞ RL = 4.3k VSHDN = VIN
12 VSHDN = VIN 1.2 *FOR VOUT = 1.5V
VSHDN = VIN 20
QUIESCENT CURRENT (mA)

QUIESCENT CURRENT (mA)

GND PIN CURRENT (mA)

10 1.0
15
8 0.8
RL = 150, IL = 10mA*
6 0.6 RL = 5, IL = 300mA*
10

4 0.4
5 RL = 15, IL = 100mA*
2 0.2

0 0 0
0 1 2 3 4 5 6 7 8 9 10 0 2 4 6 8 10 12 14 16 18 20 0 1 2 3 4 5 6 7 8 9 10
INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V)
1963A G11 1963A G12 1963A G42

LT1963A-1.8 GND Pin Current LT1963A-2.5 GND Pin Current LT1963A-3.3 GND Pin Current
25 25 25
TJ = 25°C TJ = 25°C TJ = 25°C
VSHDN = VIN VSHDN = VIN VSHDN = VIN
20 *FOR VOUT = 1.8V 20 *FOR VOUT = 2.5V 20 *FOR VOUT = 3.3V
GND PIN CURRENT (mA)
GND PIN CURRENT (mA)

GND PIN CURRENT (mA)

15 15 15
RL = 8.33, IL = 300mA*
RL = 11, IL = 300mA*
10 10 10
RL = 6, IL = 300mA*

RL = 25, IL = 100mA* RL = 33, IL = 100mA*

5 RL = 18, IL = 100mA* 5 5
RL = 180, IL = 10mA*
RL = 250, IL = 10mA* RL = 330, IL = 100mA*
0 0 0
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10
INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V)
1963A G13 1963A G14 1963A G15

Rev. G

8 For more information www.analog.com

 LT1963A Series
TYPICAL PERFORMANCE CHARACTERISTICS

LT1963A GND Pin Current LT1963A-1.5 GND Pin Current LT1963A-1.8 GND Pin Current
10 100 100
TJ = 25°C TJ = 25°C TJ = 25°C
VSHDN = VIN 90 VSHDN = VIN 90 VSHDN = VIN
*FOR VOUT = 1.21V *FOR VOUT = 1.5V 80 *FOR VOUT = 1.8V
8 80

GND PIN CURRENT (mA)

GND PIN CURRENT (mA)

GND PIN CURRENT (mA)

70 70

6 RL = 4.33, IL = 300mA* 60 RL = 1.2, IL = 1.5A*

60 RL = 1, IL = 1.5A*
50 50

4 40 RL = 1.5, IL = 1A* 40

RL = 12.1, IL = 100mA* 30 30 RL = 1.8, IL = 1A*

2 20 RL = 3, IL = 500mA* 20

10 10 RL = 3.6, IL = 500mA*
RL = 121, IL = 10mA*
0 0 0
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10
INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V)
1963A G16 1963A G43 1963A G17

LT1963A-2.5 GND Pin Current LT1963A-3.3 GND Pin Current LT1963A GND Pin Current
100 100 100
TJ = 25°C TJ = 25°C TJ = 25°C
90 VSHDN = VIN 90 VSHDN = VIN 90 VSHDN = VIN
80 *FOR VOUT = 2.5V 80 *FOR VOUT = 3.3V 80 *FOR VOUT = 1.21V
GND PIN CURRENT (mA)
GND PIN CURRENT (mA)

GND PIN CURRENT (mA)

70 70 70
RL = 1.67, IL = 1.5A* RL = 2.2, IL = 1.5A*
60 60 60
RL = 0.81, IL = 1.5A*
50 50 50
40 40 40
RL = 2.5, IL = 1A*
30 30 RL = 3.3, IL = 1A* 30
RL = 1.21, IL = 1A*
20 20 20
10 RL = 5, IL = 500mA* 10 RL = 6.6, IL = 500mA* 10 RL = 2.42, IL = 500mA*
0 0 0
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10
INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V)
1963A G18 1963A G19 1963A G20

GND Pin Current vs ILOAD SHDN Pin Threshold (On-to-Off) SHDN Pin Threshold (Off-to-On)
100 1.0 1.0
VIN = VOUT (NOMINAL) +1V IL = 1mA
90 0.9 0.9 IL = 1.5A
80 0.8 0.8
SHDN PIN THRESHOLD (V)

SHDN PIN THRESHOLD (V)

GND PIN CURRENT (mA)

70 0.7 0.7

60 0.6 0.6
IL = 1mA
50 0.5 0.5

40 0.4 0.4

30 0.3 0.3

20 0.2 0.2
10 0.1 0.1
0 0 0
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125
OUTPUT CURRENT (A) TEMPERATURE (°C) TEMPERATURE (°C)
1963A G21 1963A G22 1963A G23

Rev. G

For more information www.analog.com 9

LT1963A Series
TYPICAL PERFORMANCE CHARACTERISTICS

SHDN Pin Input Current SHDN Pin Input Current ADJ Pin Bias Current
5.0 7 5.0
VSHDN = 20V
4.5 4.5
6

SHDN PIN INPUT CURRENT (µA)

SHDN PIN INPUT CURRENT (µA)

4.0 4.0

ADJ PIN BIAS CURRENT (µA)

3.5 5 3.5
3.0 4 3.0
2.5 2.5
3
2.0 2.0
1.5 2 1.5
1.0 1.0
1
0.5 0.5
0 0 0
0 2 4 6 8 10 12 14 16 18 20 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125
SHDN PIN VOLTAGE (V) TEMPERATURE (°C) TEMPERATURE (°C)
1963A G24 1963A G25 1963A G26

Current Limit Current Limit

3.0 4.0
VIN = 7V
3.5 VOUT = 0V
2.5
TJ = 25°C 3.0
CURRENT LIMIT (A)
CURRENT LIMIT (A)

2.0 TJ = –50°C
2.5
TJ = 125°C
1.5 2.0

1.5
1.0
1.0
0.5
0.5
ΔVOUT = 100mV
0 0
0 2 4 6 8 10 12 14 16 18 20 –50 –25 0 25 50 75 100 125
INPUT/OUTPUT DIFFERENTIAL (V) TEMPERATURE (°C)
1963A G27 1963A G28

Reverse Output Current Reverse Output Current

5.0 1.0
VIN = 0V
4.5 0.9 VOUT = 1.21V (LT1963A)
LT1963A-1.8
REVERSE OUTPUT CURRENT (mA)

REVERSE OUTPUT CURRENT (mA)

V = 1.5V (LT1963A-1.5)
4.0 0.8 VOUT = 1.8V (LT1963A-1.8)
LT1963A-1.5 OUT
3.5 0.7 VOUT = 2.5V (LT1963A-2.5)
VOUT = 3.3V (LT1963A-3.3)
3.0 0.6
LT1963A LT1963A-1.8/-2.5/-3.3
2.5 0.5
2.0 0.4
LT1963A-3.3 T = 25°C
J LT1963A
1.5 VIN = 0V 0.3
LT1963A-2.5 CURRENT FLOWS INTO
1.0 0.2
OUTPUT PIN
0.5 VOUT = VADJ (LT1963A) 0.1
VOUT = VFB (LT1963A-1.5/1.8/-2.5/-3.3)
0 0
0 1 2 3 4 5 6 7 8 9 10 –50 –25 0 25 50 75 100 125
OUTPUT VOLTAGE (V) TEMPERATURE (°C)
1963A G29 1963A G30

Rev. G

10 For more information www.analog.com

 LT1963A Series
TYPICAL PERFORMANCE CHARACTERISTICS

Ripple Rejection Ripple Rejection LT1963A Minimum Input Voltage

80 76 3.0

70 74 2.5
IL = 1.5A

MINIMUM INPUT VOLTAGE (V)

60 IL = 500mA
RIPPLE REJECTION (dB)

RIPPLE REJECTION (dB)

72
2.0
50
70
40 IL = 100mA
1.5
COUT = 100µF TANTALUM 68
30 +10 × 1µF CERAMIC
1.0
COUT = 10µF TANTALUM 66
20

64 IL = 0.75A 0.5
10 IL = 0.75A
VIN = VOUT(NOMINAL) +1V + 0.5VP-P
VIN = VOUT(NOMINAL) +1V + 50mVRMS RIPPLE RIPPLE AT f = 120Hz
0 62 0
10 100 1k 10k 100k 1M –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125
FREQUENCY (Hz) TEMPERATURE (°C) TEMPERATURE (°C)
1963A G31
1963A G32 1963A G33

Load Regulation Output Noise Spectral Density

10 1.0
COUT = 10µF
OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) IL =1.5A
5
LT1963A-1.5
LOAD REGULATION (mV)

0 LT1963A
LT1963A-2.5
LT1963A-1.8 LT1963A-3.3
–5 0.1
LT1963A-2.5
LT1963A-3.3
–10
VIN = VOUT(NOMINAL) +1V LT1963A
LT1963A-1.8
–15 (LT1963A-1.8/-2.5/-3.3)
VIN = 2.7V (LT1963A/LT1963A-1.5) LT1963A-1.5
ΔIL = 1mA TO 1.5A
–20 0.01
–50 –25 0 25 50 75 100 125 10 100 1k 10k 100k
TEMPERATURE (°C) FREQUENCY (Hz)
1963A G34 1963A G35

RMS Output Noise vs Load

Current (10Hz to 100kHz) LT1963A-3.3 10Hz to 100kHz Output Noise
50
COUT = 10µF
45
OUTPUT NOISE VOLTAGE (µVRMS)

40 LT1963A-3.3
35
LT1963A-2.5
30
25 VOUT
LT1963A-1.8 100µV/DIV
20
15 LT1963A-1.5
LT1963A
10
5
0 1963A G37
0.0001 0.001 0.01 0.1 1 10 COUT = 10µF 1ms/DIV
LOAD CURRENT (A) ILOAD = 1.5A
1963A G36

Rev. G

For more information www.analog.com 11

LT1963A Series
TYPICAL PERFORMANCE CHARACTERISTICS

LT1963A-3.3 Transient Response LT1963A-3.3 Transient Response

200 150
VIN = 4.3V
150 CIN = 3.3µF TANTALUM 100
OUTPUT VOLTAGE

OUTPUT VOLTAGE
DEVIATION (mV)

COUT = 10µF TANTALUM

DEVIATION (mV)
100 50
50 0
0 –50
–50 –100
–100 –150
0.6 1.5
CURRENT (A)

CURRENT (A)
VIN = 4.3V
0.4 1.0 CIN = 33µF TANTALUM
LOAD

LOAD
0.2 COUT = 100µF TANTALUM
0.5
+10 × 1µF CERAMIC
0 0
0 2 4 6 8 10 12 14 16 18 20 0 50 100 150 200 250 300 350 400 450 500
TIME (µs) TIME (µs)
1963A G38 1963A G39

Rev. G

12 For more information www.analog.com

 LT1963A Series
PIN FUNCTIONS
OUT: Output. The output supplies power to the load. The output will be off when the SHDN pin is pulled low.
A minimum output capacitor of 10µF is required to The SHDN pin can be driven either by 5V logic or open-
prevent oscillations. Larger output capacitors will be collector logic with a pull-up resistor. The pull-up resis-
required for applications with large transient loads to limit tor is required to supply the pull-up current of the open-
peak voltage transients. See the Applications Information collector gate, normally several microamperes, and the
section for more information on output capacitance and SHDN pin current, typically 3µA. If unused, the SHDN pin
reverse output characteristics. must be connected to VIN. The device will be in the low
SENSE: Sense. For fixed voltage versions of the LT1963A power shutdown state if the SHDN pin is not connected.
(LT1963A-1.5/LT1963A-1.8/LT1963A-2.5/LT1963A-3.3), IN: Input. Power is supplied to the device through the IN
the SENSE pin is the input to the error amplifier. Optimum pin. A bypass capacitor is required on this pin if the device
regulation will be obtained at the point where the SENSE is more than six inches away from the main input filter
pin is connected to the OUT pin of the regulator. In criti- capacitor. In general, the output impedance of a battery
cal applications, small voltage drops are caused by the rises with frequency, so it is advisable to include a bypass
resistance (RP) of PC traces between the regulator and the capacitor in battery-powered circuits. A bypass capacitor
load. These may be eliminated by connecting the SENSE in the range of 1µF to 10µF is sufficient. The LT1963A
pin to the output at the load as shown in Figure 1 (Kelvin regulators are designed to withstand reverse voltages
Sense Connection). Note that the voltage drop across on the IN pin with respect to ground and the OUT pin. In
the external PC traces will add to the dropout voltage of the case of a reverse input, which can happen if a battery
the regulator. The SENSE pin bias current is 600µA at is plugged in backwards, the device will act as if there is
the nominal rated output voltage. The SENSE pin can be a diode in series with its input. There will be no reverse
pulled below ground (as in a dual supply system where current flow into the regulator and no reverse voltage
the regulator load is returned to a negative supply) and will appear at the load. The device will protect both itself
still allow the device to start and operate. and the load.
ADJ: Adjust. For the adjustable LT1963A, this is the input
IN OUT
to the error amplifier. This pin is internally clamped to ± 7V. RP
LT1963A
It has a bias current of 3µA which flows into the pin. The +
+ SHDN SENSE
ADJ pin voltage is 1.21V referenced to ground and the VIN LOAD
GND
output voltage range is 1.21V to 20V.
RP
SHDN: Shutdown. The SHDN pin is used to put the 1963A F01

LT1963A regulators into a low power shutdown state. Figure 1. Kelvin Sense Connection

Rev. G

For more information www.analog.com 13

LT1963A Series
APPLICATIONS INFORMATION
The LT1963A series are 1.5A low dropout regulators opti- IN OUT VOUT
mized for fast transient response. The devices are capable +
VIN R2
of supplying 1.5A at a dropout voltage of 350mV. The low LT1963A
 R2 
VOUT =1.21V 1+  + (IADJ ) (R2)
operating quiescent current (1mA) drops to less than 1µA ADJ
 R1 
in shutdown. In addition to the low quiescent current, the GND R1 VADJ =1.21V
LT1963A regulators incorporate several protection fea- IADJ = 3µA AT 25°C
tures which make them ideal for use in battery-powered
1963A F02
OUTPUT RANGE = 1.21V TO 20V

systems. The devices are protected against both reverse Figure 2. Adjustable Operation
input and reverse output voltages. In battery backup appli-
cations where the output can be held up by a backup bat- make it stable. For the LT1963A, the frequency compensa-
tery when the input is pulled to ground, the LT1963A‑X tion is both internal and external—the output capacitor.
acts like it has a diode in series with its output and prevents The size of the output capacitor, the type of the output
reverse current flow. Additionally, in dual supply applica- capacitor, and the ESR of the particular output capacitor
tions where the regulator load is returned to a negative all affect the stability.
supply, the output can be pulled below ground by as much In addition to stability, the output capacitor also affects
as 20V and still allow the device to start and operate. the high frequency transient response. The regulator
loop has a finite band width. For high frequency transient
Adjustable Operation loads, recovery from a transient is a combination of the
The adjustable version of the LT1963A has an output volt- output capacitor and the bandwidth of the regulator. The
age range of 1.21V to 20V. The output voltage is set by LT1963A was designed to be easy to use and accept a
the ratio of two external resistors as shown in Figure 2. wide variety of output capacitors. However, the frequency
The device servos the output to maintain the voltage at compensation is affected by the output capacitor and opti-
the ADJ pin at 1.21V referenced to ground. The current mum frequency stability may require some ESR, espe-
in R1 is then equal to 1.21V/R1 and the current in R2 is cially with ceramic capacitors.
the current in R1 plus the ADJ pin bias current. The ADJ For ease of use, low ESR polytantalum capacitors
pin bias current, 3µA at 25°C, flows through R2 into the (POSCAP) are a good choice for both the transient
ADJ pin. The output voltage can be calculated using the response and stability of the regulator. These capacitors
formula in Figure 2. The value of R1 should be less than have intrinsic ESR that improves the stability. Ceramic
4.17k to minimize errors in the output voltage caused by capacitors have extremely low ESR, and while they are a
the ADJ pin bias current. Note that in shutdown the output
good choice in many cases, placing a small series resis-
is turned off and the divider current will be zero. tance element will sometimes achieve optimum stability
The adjustable device is tested and specified with the ADJ and minimize ringing. In all cases, a minimum of 10µF is
pin tied to the OUT pin for an output voltage of 1.21V. required while the maximum ESR allowable is 3Ω.
Specifications for output voltages greater than 1.21V will The place where ESR is most helpful with ceramics is
be proportional to the ratio of the desired output voltage low output voltage. At low output voltages, below 2.5V,
to 1.21V: VOUT/1.21V. For example, load regulation for an some ESR helps the stability when ceramic output capac-
output current change of 1mA to 1.5A is – 3mV typical at itors are used. Also, some ESR allows a smaller capaci-
VOUT = 1.21V. At VOUT = 5V, load regulation is: tor value to be used. When small signal ringing occurs
(5V/1.21V)(–3mV) = –12.4mV with ceramics due to insufficient ESR, adding ESR or
increasing the capacitor value improves the stability and
Output Capacitors and Stability reduces the ringing. Table 1 gives some recommended
The LT1963A regulator is a feedback circuit. Like any values of ESR to minimize ringing caused by fast, hard
feedback circuit, frequency compensation is needed to current transitions.
Rev. G

14 For more information www.analog.com

 LT1963A Series
APPLICATIONS INFORMATION
Table 1. Capacitor Minimum ESR at the worst case value of 1.2V. Trace A, is with a 10µF
VOUT 10µF 22µF 47µF 100µF ceramic output capacitor and shows significant ringing
1.2V 20mΩ 15mΩ 10mΩ 5mΩ with a peak amplitude of 25mV. For Trace B, a 22µF/45mΩ
1.5V 20mΩ 15mΩ 10mΩ 5mΩ POSCAP is added in parallel with the 10µF ceramic. The
1.8V 15mΩ 10mΩ 10mΩ 5mΩ output is well damped and settles to within 10mV in less
2.5V 5mΩ 5mΩ 5mΩ 5mΩ than 20µs.
3.3V 0mΩ 0mΩ 0mΩ 5mΩ For Trace C, a 100µF/35mΩ POSCAP is connected in
≥5V 0mΩ 0mΩ 0mΩ 0mΩ parallel with the 10µF ceramic capacitor. In this case the
peak output deviation is less than 20mV and the output
Figure 3 through Figure 8 shows the effect of ESR on the settles in about 10µs. For improved transient response
transient response of the regulator. These scope photos the value of the bulk capacitor (tantalum or aluminum
show the transient response for the LT1963A at three dif- electrolytic) should be greater than twice the value of the
ferent output voltages with various capacitors and various ceramic capacitor.
values of ESR. The output load conditions are the same
for all traces. In all cases there is a DC load of 500mA. Tantalum and Polytantalum Capacitors
The load steps up to 1A at the first transition and steps There is a variety of tantalum capacitor types available,
back to 500mA at the second transition. with a wide range of ESR specifications. Older types
At the worst case point of 1.2VOUT with 10µF COUT have ESR specifications in the hundreds of mΩ to sev-
(Figure 3), a minimum amount of ESR is required. While eral Ohms. Some newer types of polytantalum with
20mΩ is enough to eliminate most of the ringing, a value multi-electrodes have maximum ESR specifications as
closer to 50mΩ provides a more optimum response. At low as 5mΩ. In general the lower the ESR specification,
2.5V output with 10µF COUT (Figure 4) the output rings the larger the size and the higher the price. Polytantalum
at the transitions with 0Ω ESR but still settles to within capacitors have better surge capability than older types
10mV in 20µs after the 0.5A load step. Once again a small and generally lower ESR. Some types such as the Sanyo
value of ESR will provide a more optimum response. TPE and TPB series have ESR specifications in the 20mΩ
to 50mΩ range, which provide near optimum transient
At 5VOUT with 10µF COUT (Figure 5) the response is well
response.
damped with 0Ω ESR.
With a COUT of 100µF at 0Ω ESR and an output of 1.2V Aluminum Electrolytic Capacitors
(Figure 6), the output rings although the amplitude is only Aluminum electrolytic capacitors can also be used with the
20mVp-p. With COUT of 100µF it takes only 5mΩ to 20mΩ of
LT1963A. These capacitors can also be used in conjunc-
ESR to provide good damping at 1.2V output. Performance
tion with ceramic capacitors. These tend to be the cheap-
at 2.5V and 5V output with 100µF COUT shows similar
est and lowest performance type of capacitors. Care must
characteristics to the 10µF case (see Figure 7 - Figure 8).
be used in selecting these capacitors as some types can
At 2.5VOUT 5mΩ to 20mΩ can improve transient response.
have ESR which can easily exceed the 3Ω maximum value.
At 5VOUT the response is well damped with 0Ω ESR.
Capacitor types with inherently higher ESR can be com- Ceramic Capacitors
bined with 0mΩ ESR ceramic capacitors to achieve both Extra consideration must be given to the use of ceramic
good high frequency bypassing and fast settling time. capacitors. Ceramic capacitors are manufactured with a
Figure 9 illustrates the improvement in transient response variety of dielectrics, each with different behavior over
that can be seen when a parallel combination of ceramic temperature and applied voltage. The most common
and POSCAP capacitors are used. The output voltage is dielectrics used are Z5U, Y5V, X5R and X7R. The Z5U and
Rev. G

For more information www.analog.com 15

LT1963A Series
APPLICATIONS INFORMATION
VOUT = 1.2V VOUT = 1.2V
0 IOUT = 500mA WITH 0 IOUT = 500mA WITH
500mA PULSE 500mA PULSE
COUT = 10µF COUT = 100µF
20 5
RESR (mΩ)

RESR (mΩ)
50mV/DIV

50mV/DIV
50 10

100 20

1963A F03 1963A F06

20µs/DIV 50µs/DIV

Figure 3. Figure 6.

VOUT = 2.5V VOUT = 2.5V

0 IOUT = 500mA WITH 0 IOUT = 500mA WITH
500mA PULSE 500mA PULSE
COUT = 10µF COUT = 100µF
20 5
RESR (mΩ)

RESR (mΩ)
50mV/DIV

50mV/DIV
50 10

100 20

1963A F04 1963A F07

20µs/DIV 50µs/DIV

Figure 4. Figure 7.

VOUT = 5V VOUT = 5V
0 IOUT = 500mA WITH 0 IOUT = 500mA WITH
500mA PULSE 500mA PULSE
COUT = 10µF COUT = 100µF
20 5
RESR (mΩ)

RESR (mΩ)
50mV/DIV

50mV/DIV
50 10

100 20

1963A F05 1963A F08

20µs/DIV 50µs/DIV

Figure 5. Figure 8.

VOUT = 1.2V
A IOUT = 500mA WITH 500mA PULSE
COUT =
A = 10µF CERAMIC
B = 10µF CERAMIC II 22µF/45mΩ POLY
C = 10µF CERAMIC II 100µF/35mΩ POLY
RESR (mΩ)

50mV/DIV

1963A F09
50µs/DIV

Figure 9.
Rev. G

16 For more information www.analog.com

 LT1963A Series
APPLICATIONS INFORMATION
Y5V dielectrics are good for providing high capacitances “FREE” Resistance with PC Traces
in a small package, but exhibit strong voltage and tem- The resistance values shown in Table 2 can easily be made
perature coefficients as shown in Figure 10 and Figure 11. using a small section of PC trace in series with the output
When used with a 5V regulator, a 10µF Y5V capacitor can capacitor. The wide range of non-critical ESR makes it
exhibit an effective value as low as 1µF to 2µF over the easy to use PC trace. The trace width should be sized to
operating temperature range. The X5R and X7R dielec-
handle the RMS ripple current associated with the load.
trics result in more stable characteristics and are more
The output capacitor only sources or sinks current for a
suitable for use as the output capacitor. The X7R type has
few microseconds during fast output current transitions.
better stability across temperature, while the X5R is less
There is no DC current in the output capacitor. Worst case
expensive and is available in higher values.
ripple current will occur if the output load is a high fre-
Voltage and temperature coefficients are not the only quency (>100kHz) square wave with a high peak value and
sources of problems. Some ceramic capacitors have a fast edges (< 1µs). Measured RMS value for this case is
piezoelectric response. A piezoelectric device generates 0.5 times the peak-to-peak current change. Slower edges
voltage across its terminals due to mechanical stress, or lower frequency will significantly reduce the RMS ripple
similar to the way a piezoelectric accelerometer or micro- current in the capacitor.
phone works. For a ceramic capacitor the stress can be
induced by vibrations in the system or thermal transients.

Table 2. PC Trace Resistors

10mΩ 20mΩ 30mΩ
0.5oz CU Width 0.011" (0.28mm) 0.011" (0.28mm) 0.011" (0.28mm)
Length 0.102" (2.6mm) 0.204" (5.2mm) 0.307" (7.8mm)
1.0oz CU Width 0.006" (0.15mm) 0.006" (0.15mm) 0.006" (0.15mm)
Length 0.110" (2.8mm) 0.220" (5.6mm) 0.330" (8.4mm)
2.0oz CU Width 0.006" (0.15mm) 0.006" (0.15mm) 0.006" (0.15mm)
Length 0.224" (5.7mm) 0.450" (11.4mm) 0.670" (17mm)

20 40
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10µF
20
0
X5R X5R
CHANGE IN VALUE (%)

CHANGE IN VALUE (%)

0
–20
–20
–40
–40
Y5V
–60
Y5V –60

–80 –80 BOTH CAPACITORS ARE 16V,

1210 CASE SIZE, 10µF
–100 –100
0 2 4 6 8 10 12 14 16 –50 –25 0 25 50 75 100 125
DC BIAS VOLTAGE (V) TEMPERATURE (°C)
1963A F10 1963A F11

Figure 10. Ceramic Capacitor DC Bias Characteristics Figure 11. Ceramic Capacitor Temperature Characteristics

Rev. G

For more information www.analog.com 17

LT1963A Series
APPLICATIONS INFORMATION
This resistor should be made using one of the inner Output Voltage Noise
layers of the PC board which are well defined. The resistiv-
The LT1963A regulators have been designed to provide
ity is determined primarily by the sheet resistance of the
low output voltage noise over the 10Hz to 100kHz band-
copper laminate with no additional plating steps. Table 2
width while operating at full load. Output voltage noise is
gives some sizes for 0.75A RMS current for various cop-
typically 40nV/√Hz over this frequency bandwidth for the
per thicknesses. More detailed information regarding
LT1963A (adjustable version). For higher output voltages
resistors made from PC traces can be found in Application
(generated by using a resistor divider), the output voltage
Note 69, Appendix A. noise will be gained up accordingly. This results in RMS
noise over the 10Hz to 100kHz bandwidth of 14µVRMS for
Overload Recovery
the LT1963A increasing to 38µVRMS for the LT1963A-3.3.
Like many IC power regulators, the LT1963A-X has
Higher values of output voltage noise may be measured
safe operating area protection. The safe area protection
when care is not exercised with regard to circuit layout
decreases the current limit as input-to-output voltage
and testing. Crosstalk from nearby traces can induce
increases and keeps the power transistor inside a safe
unwanted noise onto the output of the LT1963A-X. Power
operating region for all values of input-to-output voltage.
supply ripple rejection must also be considered; the
The protection is designed to provide some output current
LT1963A regulators do not have unlimited power supply
at all values of input-to-output voltage up to the device
rejection and will pass a small portion of the input noise
breakdown.
through to the output.
When power is first turned on, as the input voltage rises,
the output follows the input, allowing the regulator to start Thermal Considerations
up into very heavy loads. During the start-up, as the input The power handling capability of the device is limited
voltage is rising, the input-to-output voltage differential by the maximum rated junction temperature (125°C).
is small, allowing the regulator to supply large output The power dissipated by the device is made up of two
currents. With a high input voltage, a problem can occur components:
wherein removal of an output short will not allow the
output voltage to recover. Other regulators, such as the 1. Output current multiplied by the input/output voltage
LT1085, also exhibit this phenomenon, so it is not unique differential: (IOUT)(VIN – VOUT), and
to the LT1963A-X. 2. GND pin current multiplied by the input voltage: (IGND)
The problem occurs with a heavy output load when (VIN).
the input voltage is high and the output voltage is low. The GND pin current can be found using the GND Pin
Common situations are immediately after the removal of Current curves in the Typical Performance Characteristics.
a short-circuit or when the shutdown pin is pulled high Power dissipation will be equal to the sum of the two com-
after the input voltage has already been turned on. The ponents listed above.
load line for such a load may intersect the output cur- The LT1963A series regulators have internal thermal
rent curve at two points. If this happens, there are two limiting designed to protect the device during overload
stable output operating points for the regulator. With this conditions. For continuous normal conditions, the maxi-
double intersection, the input power supply may need to mum junction temperature rating of 125°C must not be
be cycled down to zero and brought up again to make the exceeded. It is important to give careful consideration to
output recover. all sources of thermal resistance from junction to ambi-
ent. Additional heat sources mounted nearby must also
be considered.

Rev. G

18 For more information www.analog.com

 LT1963A Series
APPLICATIONS INFORMATION
For surface mount devices, heat sinking is accomplished to 500mA and a maximum ambient temperature of 50°C,
by using the heat spreading capabilities of the PC board what will the maximum junction temperature be?
and its copper traces. Copper board stiffeners and plated The power dissipated by the device will be equal to:
through-holes can also be used to spread the heat gener-
ated by power devices. IOUT(MAX)(VIN(MAX) – VOUT) + IGND(VIN(MAX))
The following tables list thermal resistance for several where,
different board sizes and copper areas. All measure- IOUT(MAX) = 500mA
ments were taken in still air on 1/16" FR-4 board with VIN(MAX) = 6V
one ounce copper. IGND at (IOUT = 500mA, VIN = 6V) = 10mA
Table 3. Q Package, 5-Lead DD So,
COPPER AREA THERMAL RESISTANCE P = 500mA(6V – 3.3V) + 10mA(6V) = 1.41W
TOPSIDE* BACKSIDE BOARD AREA (JUNCTION-TO-AMBIENT)
2500mm2 2500mm2 2500mm2 23°C/W Using a DD package, the thermal resistance will be in the
1000mm2 2500mm2 2500mm2 25°C/W range of 23°C/W to 33°C/W depending on the copper
125mm2 2500mm2 2500mm2 33°C/W area. So the junction temperature rise above ambient will
*Device is mounted on topside
be approximately equal to:
1.41W(28°C/W) = 39.5°C
Table 4. S0-8 Package, 8-Lead SO
COPPER AREA THERMAL RESISTANCE
The maximum junction temperature will then be equal to
TOPSIDE* BACKSIDE BOARD AREA (JUNCTION-TO-AMBIENT) the maximum junction temperature rise above ambient
2500mm2 2500mm2 2500mm2 55°C/W plus the maximum ambient temperature or:
1000mm2 2500mm2 2500mm2 55°C/W TJMAX = 50°C + 39.5°C = 89.5°C
225mm2 2500mm2 2500mm2 63°C/W
125mm2 2500mm2 2500mm2 69°C/W Protection Features
*Device is mounted on topside The LT1963A regulators incorporate several protection
features which make them ideal for use in battery-pow-
Table 5. SOT-223 Package, 3-Lead SOT-223
ered circuits. In addition to the normal protection features
COPPER AREA THERMAL RESISTANCE
TOPSIDE* BACKSIDE BOARD AREA (JUNCTION-TO-AMBIENT)
associated with monolithic regulators, such as current
limiting and thermal limiting, the devices are protected
2500mm2 2500mm2 2500mm2 42°C/W
against reverse input voltages, reverse output voltages
1000mm2 2500mm2 2500mm2 42°C/W
and reverse voltages from output to input.
225mm2 2500mm2 2500mm2 50°C/W
100mm2 2500mm2 2500mm2 56°C/W
Current limit protection and thermal overload protection
1000mm2 1000mm2 1000mm2 49°C/W
are intended to protect the device against current overload
conditions at the output of the device. For normal opera-
1000mm2 0mm2 1000mm2 52°C/W
tion, the junction temperature should not exceed 125°C.
*Device is mounted on topside
The input of the device will withstand reverse voltages of
T Package, 5-Lead TO-220
Thermal Resistance (Junction-to-Case) = 4°C/W
20V. Current flow into the device will be limited to less
than 1mA (typically less than 100µA) and no negative
Calculating Junction Temperature voltage will appear at the output. The device will protect
both itself and the load. This provides protection against
Example: Given an output voltage of 3.3V, an input volt- batteries that can be plugged in backward.
age range of 4V to 6V, an output current range of 0mA

Rev. G

For more information www.analog.com 19

LT1963A Series
APPLICATIONS INFORMATION
The output of the LT1963A can be pulled below ground In circuits where a backup battery is required, several
without damaging the device. If the input is left open cir- different input/output conditions can occur. The output
cuit or grounded, the output can be pulled below ground voltage may be held up while the input is either pulled
by 20V. For fixed voltage versions, the output will act like a to ground, pulled to some intermediate voltage, or is left
large resistor, typically 5k or higher, limiting current flow open circuit. Current flow back into the output will follow
to typically less than 600µA. For adjustable versions, the the curve shown in Figure 12.
output will act like an open circuit; no current will flow out
of the pin. If the input is powered by a voltage source, the When the IN pin of the LT1963A is forced below the OUT
output will source the short-circuit current of the device pin or the OUT pin is pulled above the IN pin, input cur-
and will protect itself by thermal limiting. In this case, rent will typically drop to less than 2µA. This can happen
grounding the SHDN pin will turn off the device and stop if the input of the device is connected to a discharged
the output from sourcing the short-circuit current. (low voltage) battery and the output is held up by either
a backup battery or a second regulator circuit. The state
The ADJ pin of the adjustable device can be pulled above of the SHDN pin will have no effect on the reverse output
or below ground by as much as 7V without damaging the current when the output is pulled above the input.
device. If the input is left open circuit or grounded, the
ADJ pin will act like an open circuit when pulled below
5.0
ground and like a large resistor (typically 5k) in series with LT1963A
4.5 VOUT = VADJ
a diode when pulled above ground. REVERSE OUTPUT CURRENT (mA) 4.0 LT1963A-1.5
In situations where the ADJ pin is connected to a resistor 3.5
VOUT = VFB
LT1963A-1.8
divider that would pull the ADJ pin above its 7V clamp 3.0 VOUT = VFB
voltage if the output is pulled high, the ADJ pin input cur- 2.5 LT1963A-2.5
VOUT = VFB
rent must be limited to less than 5mA. For example, a 2.0
LT1963A-3.3
resistor divider is used to provide a regulated 1.5V output 1.5 VOUT = VFB
TJ = 25°C
from the 1.21V reference when the output is forced to 20V. 1.0
VIN = 0V
The top resistor of the resistor divider must be chosen to 0.5 CURRENT FLOWS
INTO OUTPUT PIN
limit the current into the ADJ pin to less than 5mA when 0
0 1 2 3 4 5 6 7 8 9 10
the ADJ pin is at 7V. The 13V difference between OUT OUTPUT VOLTAGE (V) 1963A F12

and ADJ pins divided by the 5mA maximum current into

the ADJ pin yields a minimum top resistor value of 2.6k. Figure 12. Reverse Output Current

Rev. G

20 For more information www.analog.com

 LT1963A Series
TYPICAL APPLICATIONS
SCR Pre-Regulator Provides Efficiency Over Line Variations

L1
500µH LT1963A-3.3
3.3VOUT
IN OUT
L2 1N4148 1.5A
10VAC AT
+ +
10000µF SHDN FB 22µF
115VIN GND
90-140 1k
VAC 34k*
10VAC AT
115VIN

1N4002 1N4002 12.1k*

+V
“SYNC”

1N4002 2.4k
TO ALL “+V” C1A
+ 200k
POINTS + 1/2
1N4148
22µF 750Ω LT1018
– 0.1µF

+V

C1B
750Ω + +V
0.033µF
1/2 A1 +
LT1018 1N4148
–
LT1006
– 10k 10k
+V
10k
1µF

+V

L1 = COILTRONICS CTX500-2-52 LT1004

L2 = STANCOR P-8559 1.2V
* = 1% FILM RESISTOR
= NTE5437 1963A TA03

Paralleling of Regulators for Higher Output Current

R1, 0.01Ω LT1963A-3.3 3.3V

IN OUT
+ + 3A
VIN > 3.7V C1 C2
100µF SHDN FB 22µF
GND

R2
0.01Ω LT1963A
IN OUT
R6
6.65k
SHDN SHDN FB
GND R7
4.12k

R3 R4 R5
2.2k 2.2k 1k
3 8
+
1/2 1
2 LT1366
– 4 C3
0.01µF

1963A TA05

Rev. G

For more information www.analog.com 21

LT1963A Series
PACKAGE DESCRIPTION
Q Package
5-Lead Plastic DD Pak
(Reference LTC DWG # 05-08-1461 Rev F)

.060
(1.524) .390 – .415
.060 TYP (9.906 – 10.541) .165 – .180
.256
(6.502) (1.524) (4.191 – 4.572) .045 – .055
15° TYP (1.143 – 1.397)

+.008
.004 –.004
.060 .183 .059

( )
.330 – .370
(1.524) (4.648) (1.499) +0.203
(8.382 – 9.398) TYP 0.102 –0.102

.095 – .115
(2.413 – 2.921)
.075
(1.905) DETAIL A
.067 .050 ±.012
.300 +.012 .013 – .023
.143 –.020 (1.702) (1.270 ±0.305)
(7.620) (0.330 – 0.584)
.028 – .038 BSC
BOTTOM VIEW OF DD PAK
HATCHED AREA IS SOLDER PLATED
( +0.305
3.632 –0.508 ) (0.711 – 0.965)
TYP
COPPER HEAT SINK

DETAIL A

0° – 7° TYP 0° – 7° TYP

.420
.080
.420 .276

.350 .325
.205
.585 .585

.320

.090 .090

.067 .042 .067 .042

RECOMMENDED SOLDER PAD LAYOUT RECOMMENDED SOLDER PAD LAYOUT

FOR THICKER SOLDER PASTE APPLICATIONS
NOTE:
1. DIMENSIONS IN INCH/(MILLIMETER) Q(DD5) 0811 REV F

2. DRAWING NOT TO SCALE

Rev. G

22 For more information www.analog.com

 LT1963A Series
PACKAGE DESCRIPTION
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)

.189 – .197
.045 ±.005 (4.801 – 5.004)
.050 BSC NOTE 3
8 7 6 5

.245
MIN .160 ±.005
.150 – .157
.228 – .244
(3.810 – 3.988)
(5.791 – 6.197)
NOTE 3

.030 ±.005
TYP
1 2 3 4
RECOMMENDED SOLDER PAD LAYOUT

.010 – .020
× 45° .053 – .069
(0.254 – 0.508)
(1.346 – 1.752)
.004 – .010
.008 – .010
0°– 8° TYP (0.101 – 0.254)
(0.203 – 0.254)

.016 – .050
.014 – .019 .050
(0.406 – 1.270)
(0.355 – 0.483) (1.270)
NOTE: TYP BSC
INCHES
1. DIMENSIONS IN
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) SO8 REV G 0212

4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE

Rev. G

For more information www.analog.com 23

LT1963A Series
PACKAGE DESCRIPTION
ST Package
3-Lead Plastic SOT-223
(Reference LTC DWG # 05-08-1630)

.248 – .264 .129 MAX

(6.30 – 6.71)
.114 – .124
(2.90 – 3.15) .059 MAX

.264 – .287 .248 BSC

(6.70 – 7.30)

.130 – .146
(3.30 – 3.71)
.039 MAX

.059 MAX

.090
BSC
.181 MAX
.0905 .033 – .041
RECOMMENDED SOLDER PAD LAYOUT
(2.30) (0.84 – 1.04)
BSC

10° – 16°
.010 – .014
.071 10°
(0.25 – 0.36)
(1.80) MAX
MAX

10° – 16°
.024 – .033 .012 .0008 – .0040
(0.60 – 0.84) (0.31) (0.0203 – 0.1016)
.181 MIN
ST3 (SOT-233) 0502
(4.60)
BSC

Rev. G

24 For more information www.analog.com

 LT1963A Series
PACKAGE DESCRIPTION
T-Package
5-Lead Plastic TO-220 (Standard)
(Reference LTC DWG # 05-08-1421)

.147 – .155 .165 – .180

.390 – .415 (3.734 – 3.937) (4.191 – 4.572) .045 – .055
(9.906 – 10.541) DIA (1.143 – 1.397)

.230 – .270
(5.842 – 6.858)
.570 – .620
.620
.460 – .500 (14.478 – 15.748)
(15.75)
(11.684 – 12.700) TYP
.330 – .370
.700 – .728
(8.382 – 9.398)
(17.78 – 18.491)

.095 – .115
SEATING PLANE
(2.413 – 2.921)
.152 – .202
.260 – .320 (3.861 – 5.131) .155 – .195*
(6.60 – 8.13) (3.937 – 4.953)

.013 – .023
(0.330 – 0.584)
.067
BSC .028 – .038 .135 – .165
(1.70)
(0.711 – 0.965) (3.429 – 4.191) * MEASURED AT THE SEATING PLANE
T5 (TO-220) 0801

Rev. G

For more information www.analog.com 25

LT1963A Series
PACKAGE DESCRIPTION
FE Package
16-Lead Plastic TSSOP (4.4mm)
(Reference LTC DWG # 05-08-1663 Rev L)
Exposed Pad Variation BB
DETAIL A
4.70 0.56
(.185) 4.90 – 5.10* (.022)
3.70 (.193 – .201) REF
(.146)
3.70 ±0.15 0.53
(.146 ±.006) (.021)
NOTE 5 16 1514 13 12 1110 9 REF
DETAIL A IS THE PART OF THE
NOTE 5 LEAD FRAME FEATURE FOR
6.60 ±0.10 REFERENCE ONLY
2.94 3.05 NO MEASUREMENT PURPOSE
4.50 ±0.10 (.116) (.120) DETAIL A
SEE NOTE 4 2.94 ±0.15 6.40 ±0.15
(.116 ±.006) (.252 ±.006)

1.05 ±0.10

0.65 BSC 0.45 ±0.05

RECOMMENDED SOLDER PAD LAYOUT 1 2 3 4 5 6 7 8
1.10
4.30 – 4.50* (.0433)
(.169 – .177) 0.25 MAX
REF
0° – 8°

0.65
0.09 – 0.20 0.50 – 0.75 (.0256) 0.05 – 0.15
(.0035 – .0079) (.020 – .030) BSC (.002 – .006)
0.195 – 0.30
FE16 (BB) TSSOP REV L 1216
(.0077 – .0118)
TYP
NOTE:
1. CONTROLLING DIMENSION: MILLIMETERS 5. BOTTOM EXPOSED PADDLE MAY HAVE METAL PROTRUSION
MILLIMETERS IN THIS AREA. THIS REGION MUST BE FREE OF ANY EXPOSED
2. DIMENSIONS ARE IN TRACES OR VIAS ON PCB LAYOUT
(INCHES)
3. DRAWING NOT TO SCALE *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.150mm (.006") PER SIDE
4. RECOMMENDED MINIMUM PCB METAL SIZE
FOR EXPOSED PAD ATTACHMENT

Rev. G

26 For more information www.analog.com

 LT1963A Series
REVISION HISTORY (Revision history begins at Rev E)

REV DATE DESCRIPTION PAGE NUMBER

E 02/11 Updated FE and Q package drawings in Package Description section. 22, 26
F 09/13 Replaced graphs with correct versions. 16
G 02/21 Added AEC-Q100 Qualified for Automotive Applications to Features table. 1
Changed TJMAX in the Pin Configuration section from 150°C to 125°C. 2
Added automotive products table (#W). 4

Rev. G

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
subject to change without notice. No license For more by
is granted information www.analog.com
implication or otherwise under any patent or patent rights of Analog Devices. 27
LT1963A Series
TYPICAL APPLICATION
Adjustable Current Source

R5
0.01Ω LT1963A-1.8
IN OUT LOAD
C1
+ R1
VIN > 2.7V 1k SHDN FB
10µF
LT1004-1.2 GND
R2 R4 R6 R8
C3
80.6k 2.2k 2.2k 100k
1µF

R3
2k R7
2 8 470Ω
+
1/2 1
LT1366
3
C2
– 4
NOTE: ADJUST R1 FOR 3.3µF
0A TO 1.5A CONSTANT CURRENT 1963A TA04

RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LT1175 500mA, Micropower, Negative LDO VIN: –20V to –4.3V, VOUT(MIN) = –3.8V, VDO = 0.50V, IQ = 45µA, ISD 10µA,
DD, SOT-223, PDIP8 Packages
LT1185 3A, Negative LDO VIN: –35V to –4.2V, VOUT(MIN) = –2.40V, VDO = 0.80V, IQ = 2.5mA, ISD <1µA,
TO220-5 Package
LT1761 100mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 20µA, ISD <1µA
ThinSOT™ Package
LT1762 150mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 25µA, ISD <1µA, MS8 Package
LT1763 500mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 30µA, ISD <1µA, S8 Package
LT1764/ 3A, Low Noise, Fast Transient Response, VIN: 2.7V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD <1µA,
LT1764A LDO DD, TO220 Packages
LTC1844 150mA, Very Low Drop-Out LDO VIN: 6.5V to 1.6V, VOUT(MIN) = 1.25V, VDO = 0.08V, IQ = 40µA, ISD < 1µA,
ThinSOT Package
LT1962 300mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.27V, IQ = 30µA, ISD <1µA, MS8 Package

LT1964 200mA, Low Noise Micropower, VIN: –0.9V to –20V, VOUT(MIN) = –1.21V, VDO = 0.34V, IQ = 30µA, ISD 3µA,
Negative LDO ThinSOT Package
LT1965 1.1A, Low Noise, Low Dropout Linear 290mV Dropout Voltage, Low Noise: 40µVRMS, VIN: 1.8V to 20V, VOUT: 1.2V to 19.5V,
Regulator stable with ceramic caps, TO-220, DD-Pak, MSOP and 3mm × 3mm DFN Packages
LT3020 100mA, Low Voltage VLDO, VIN: 0.9V to 10V, VOUT(MIN) = 0.20, VDO = 0.15V, IQ = 120µA, ISD <3µA,
VIN(MIN) = 0.9V DFN, MS8 Packages
LT3023 Dual, 2x 100mA, Low Noise VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40µA, ISD <1µA,
Micropower, LDO DFN, MS10 Packages
LT3024 Dual, 100mA/500mA, Low Noise VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60µA, ISD <1µA,
Micropower, LDO DFN, TSSOP Packages
LT3080/ 1.1A, Parallelable, Low Noise, Low 300mV Dropout Voltage (2-Supply Operation), Low Noise: 40µVRMS, VIN: 1.2V to 36V,
LT3080-1 Dropout Linear Regulator VOUT: 0V to 35.7V, current-based reference with 1-resistor VOUT set; directly parallelable
(no op amp required), stable with ceramic caps, TO-220, SOT-223, MSOP and 3mm × 3mm
DFN Packages; “–1” version has integrated internal ballast resistor

Rev. G

28
02/21
www.analog.com
For more information www.analog.com  ANALOG DEVICES, INC. 2005-2021
Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Analog Devices Inc.:

LT1963AEQ-3.3#PBF LT1963AIQ#PBF LT1963AET-2.5#06PBF LT1963AET#06PBF LT1963AEFE-1.8#TRPBF
LT1963AES8-3.3#PBF LT1963AES8-1.5#TRPBF LT1963AEST-1.8#TRPBF LT1963AMPQ#PBF LT1963AET-
3.3#30PBF LT1963AEFE#PBF LT1963AIS8#PBF LT1963AEFE-3.3#PBF LT1963AET#PBF LT1963AEST-
2.5#TRPBF LT1963AEQ-1.8 LT1963AIS8#TRPBF LT1963AEQ-1.8#TRPBF LT1963AET-1.5#PBF LT1963AEST-
1.5#PBF LT1963AEQ#PBF LT1963AES8-1.8#TRPBF LT1963AET-1.8#30PBF LT1963AEFE-1.5#PBF LT1963AET-
3.3#PBF LT1963AES8#PBF LT1963AEQ-2.5#TRPBF LT1963AET-1.8#PBF LT1963AES8-1.5#PBF LT1963AIT#PBF
LT1963AEST-3.3#TRPBF LT1963AES8-2.5#TRPBF LT1963AEQ-1.8#PBF LT1963AEST-3.3#PBF LT1963AEFE-
1.8#PBF LT1963AEQ-3.3#TRPBF LT1963AET-3.3#06PBF LT1963AEST-1.5#TRPBF LT1963AET-1.8#06PBF
LT1963AES8-2.5#PBF LT1963AIFE#TRPBF LT1963AIFE#PBF LT1963AES8-3.3#TRPBF LT1963AEST-2.5#PBF
LT1963AMPS8#PBF LT1963AEQ#TRPBF LT1963AET-2.5#PBF LT1963AEFE-2.5#PBF LT1963AEFE-2.5#TRPBF
LT1963AEFE#TRPBF LT1963AES8-1.8#PBF LT1963AEFE-1.5#TRPBF LT1963AEST-1.8#PBF LT1963AEQ-
1.5#PBF LT1963AEQ-2.5#PBF LT1963AIQ#TRPBF LT1963AET-1.5#06PBF LT1963AEQ-1.5#TRPBF LT1963AET-
2.5#30PBF LT1963AMPQ#TRPBF LT1963AEFE-3.3#TRPBF LT1963AES8#TRPBF