ANALOG DEVICES LT 1963 EQ Datasheet

FEATURES

■

Optimized for Fast Transient Response

■

Output Current: 1.5A

■

Dropout Voltage: 340mV

■

Low Noise: 40µV

■

1mA Quiescent Current

■

No Protection Diodes Needed

■

Controlled Quiescent Current in Dropout

■

Fixed Output Voltages: 1.5V, 1.8V, 2.5V, 3.3V

■

Adjustable Output from 1.21V to 20V

■

<1µA Quiescent Current in Shutdown

■

Stable with 10µF Output Capacitor

■

Reverse Battery Protection

■

No Reverse Current

■

Thermal Limiting

■

5-Lead TO-220, DD, 3-Lead SOT-223, 8-Lead SO

(10Hz to 100kHz)

RMS

and 16-Lead TSSOP Packages

U

APPLICATIO S

■

3.3V to 2.5V Logic Power Supplies

■

Post Regulator for Switching Supplies

LT1963 Series

1.5A, Low Noise,

Fast Transient Response

LDO Regulators

U

DESCRIPTIO

The LT
for fast transient response. The devices are capable of
supplying 1.5A of output current with a dropout voltage of
340mV. Operating quiescent current is 1mA, dropping to
<1µA in shutdown. Quiescent current is well controlled; it
does not rise in dropout as it does with many other
regulators. In addition to fast transient response, the
LT1963 regulators have very low output noise which
makes them ideal for sensitive RF supply applications.

Output voltage range is from 1.21V to 20V. The LT1963
regulators are stable with output capacitors as low as
10µF. Internal protection circuitry includes reverse battery
protection, current limiting, thermal limiting and reverse
current protection. The devices are available in fixed
output voltages of 1.5V, 1.8V, 2.5V, 3.3V and as an
adjustable device with a 1.21V reference voltage. The
LT1963 regulators are available in 5-lead TO-220, DD,
3-lead SOT-223, 8-lead SO, and Exposed Pad 16-lead
TSSOP packages.

®

1963 series are low dropout regulators optimized

, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents,
including 6118263, 6144250.

TYPICAL APPLICATION

3.3V to 2.5V Regulator

IN

V

> 3V

IN

10µF

SHDN

OUT

LT1963-2.5

SENSE

GND

U

Dropout Voltage

400

350

300

2.5V

++

1.5A

10µF

1963 TA01

250

200

150

DROPOUT VOLTAGE (mV)

100

50

0

0.2

0

0.4
OUTPUT CURRENT (A)

0.6

0.8

1.0

1.2

1.4

1963 TA02

1.6

1963fc

1

LT1963 Series

1

2

3

4

8

7

6

5

TOP VIEW

IN

GND

GND

SHDN

OUT

SENSE/ADJ*

GND

NC

S8 PACKAGE

8-LEAD PLASTIC SO

FE PACKAGE

16-LEAD PLASTIC TSSOP

EXPOSED PAD (PIN 17) IS GND. MUST BE

SOLDERED TO THE PCB.

1

2

3

4

5

6

7

8

TOP VIEW

16

15

14

13

12

11

10

9

GND

NC

OUT

OUT

OUT

SENSE/ADJ*

GND

GND

GND

NC

IN

IN

IN

NC

SHDN

GND

17

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

IN Pin Voltage ........................................................ ± 20V

OUT Pin Voltage .................................................... ±20V

Input to Output Differential Voltage (Note 2) ......... ±20V

SENSE Pin Voltage ............................................... ±20V

ADJ Pin Voltage ...................................................... ±7V

UU

W

PACKAGE/ORDER I FOR ATIO

FRONT VIEW

5

SENSE/ADJ*

4

TAB IS

GND

Q PACKAGE

5-LEAD PLASTIC DD

*PIN 5 = SENSE FOR LT1963-1.5/LT1963-1.8/

LT1963-2.5/LT1963-3.3

= ADJ FOR LT1963

T

= 150°C, θJA = 30°C/ W

JMAX

OUT

3

GND

2

IN

1

SHDN

ORDER PART NUMBER

LT1963EQ
LT1963EQ-1.5
LT1963EQ-1.8
LT1963EQ-2.5
LT1963EQ-3.3

TAB IS

GND

*PIN 5 = SENSE FOR LT1963-1.5/LT1963-1.8/

ORDER PART NUMBER

FRONT VIEW

5

4

3

2

1

T PACKAGE

5-LEAD PLASTIC TO-220

LT1963-2.5/LT1963-3.3

= ADJ FOR LT1963

= 150°C, θJA = 50°C/ W

T

JMAX

LT1963ET
LT1963ET-1.5
LT1963ET-1.8
LT1963ET-2.5
LT1963ET-3.3

SHDN Pin Voltage ................................................. ± 20V

Output Short-Circuit Duration ......................... Indefinite

Operating Junction Temperature Range –40°C to 125°C

Storage Temperature Range ................. –65°C to 150°C

Lead Temperature (Soldering, 10 sec)..................300°C

SENSE/
ADJ*

OUT

GND

IN

SHDN

T

= 150°C, θJA = 38°C/ W

JMAX

*PIN 6 = SENSE FOR LT1963-1.5/

LT1963-1.8/LT1963-2.5/
LT1963-3.3

= ADJ FOR LT1963

ORDER PART NUMBER FE PART MARKING

LT1963EFE
LT1963EFE-1.5
LT1963EFE-1.8
LT1963EFE-2.5
LT1963EFE-3.3

1963EFE
1963EFE15
1963EFE18
1963EFE25
1963EFE33

ORDER PART NUMBER

LT1963EST-1.5
LT1963EST-1.8
LT1963EST-2.5
LT1963EST-3.3

Order Options

Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: http://www.linear.com/leadfree/

Consult LTC Marketing for parts specified with wider operating temperature ranges.

2

TAB IS

GND

3-LEAD PLASTIC SOT-223

T

JMAX

Tape and Reel: Add #TR

FRONT VIEW

3

OUT

2

GND

1

IN

ST PACKAGE

= 150°C, θJA = 50°C/ W

ST PART MARKING

196315
196318
196325
196333

*PIN 2 = SENSE FOR LT1963-1.5/LT1963-1.8/

LT1963-2.5/LT1963-3.3

= ADJ FOR LT1963

T

= 150°C, θJA = 70°C/ W

JMAX

ORDER PART NUMBER S8 PART MARKING

LT1963ES8
LT1963ES8-1.5
LT1963ES8-1.8
LT1963ES8-2.5
LT1963ES8-3.3

1963
196315
196318
196325
196333

1963fc

LT1963 Series

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. (Note 3)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Minimum Input Voltage (Notes 4,12) I

Regulated Output Voltage (Note 5) LT1963-1.5 VIN = 2.21V, I

ADJ Pin Voltage LT1963 VIN = 2.21V, I
(Notes 4, 5) 2.5V < V

Line Regulation LT1963-1.5 ∆VIN = 2.21V to 20V, I

Load Regulation LT1963-1.5 VIN = 2.5V, ∆I

Dropout Voltage I

= V

V

IN

OUT(NOMINAL)

(Notes 6, 7, 12)

GND Pin Current I

= V

V

IN

OUT(NOMINAL)

+ 1V I

(Notes 6, 8)

Output Voltage Noise C
ADJ Pin Bias Current (Notes 4, 9) 3 10 µA
Shutdown Threshold V

SHDN Pin Current V
(Note 10) V

Quiescent Current in Shutdown VIN = 6V, V
Ripple Rejection VIN – V

= 0.5A 1.9 V

LOAD

= 1.5A 2.5V < VIN < 20V, 1mA < I

I

LOAD

= 1mA 1.477 1.500 1.523 V

LOAD

2.5V < V

LT1963-1.8 VIN = 2.3V, I

2.8V < V

LT1963-2.5 VIN = 3V, I

3.5V < V

LT1963-3.3 VIN = 3.8V, I

4.3V < V

LT1963-1.8 ∆V
LT1963-2.5 ∆V
LT1963-3.3 ∆V
LT1963 (Note 4) ∆V

V

LT1963-1.8 VIN = 2.8V, ∆I

V

LT1963-2.5 VIN = 3.5V, ∆I

V

LT1963-3.3 VIN = 4.3V, ∆I

V

LT1963 (Note 4) VIN = 2.5V, ∆I

V

= 1mA 0.02 0.06 V

LOAD

I

= 1mA

LOAD

I

= 100mA 0.10 0.17 V

LOAD

= 100mA

I

LOAD

I

= 500mA 0.19 0.27 V

LOAD

I

= 500mA

LOAD

I

= 1.5A 0.34 0.45 V

LOAD

= 1.5A

I

LOAD

= 0mA

LOAD

= 1mA

LOAD

I

= 100mA

LOAD

= 500mA

I

LOAD

= 1.5A

I

LOAD

= 10µF, I

OUT

= Off to On

OUT

V

= On to Off

OUT

= 0V 0.01 1 µA

SHDN

= 20V 3 30 µA

SHDN

OUT

f

= 120Hz, I

RIPPLE

= 1.5A, BW = 10Hz to 100kHz 40 µV

LOAD

= 0V 0.01 1 µA

SHDN

= 1.5V (Avg), V

LOAD

< 20V, 1mA < I

IN

LOAD

< 20V, 1mA < I

IN

LOAD

< 20V, 1mA < I

IN

LOAD

< 20V, 1mA < I

IN

LOAD

< 20V, 1mA < I

IN

= 2.3V to 20V, I

IN

= 3V to 20V, I

IN

= 3.8V to 20V, I

IN

= 2.21V to 20V, I

IN

= 2.5V, ∆I

IN

= 2.8V, ∆I

IN

= 3.5V, ∆I

IN

= 4.3V, ∆I

IN

= 2.5V, ∆I

IN

LOAD
LOAD

LOAD
LOAD

LOAD
LOAD

LOAD
LOAD

LOAD
LOAD

RIPPLE

= 0.75A

= 1mA 1.773 1.800 1.827 V

= 1mA 2.462 2.500 2.538 V

= 1mA 3.250 3.300 3.350 V

= 1mA 1.192 1.210 1.228 V

LOAD

LOAD

LOAD

= 1mA to 1.5A 2 9 mV
= 1mA to 1.5A

= 1mA to 1.5A 2 10 mV
= 1mA to 1.5A

= 1mA to 1.5A 2.5 15 mV
= 1mA to 1.5A

= 1mA to 1.5A 3 20 mV
= 1mA to 1.5A

= 1mA to 1.5A 2 8 mV
= 1mA to 1.5A

= 0.5V

< 1.5A

LOAD

< 1.5A

LOAD

< 1.5A

LOAD

< 1.5A

LOAD

< 1.5A

LOAD

< 1.5A

LOAD

= 1mA

LOAD

= 1mA

= 1mA

= 1mA

= 1mA

LOAD

,5563dB

P-P

●

●

1.447 1.500 1.545 V

●

1.737 1.800 1.854 V

●

2.412 2.500 2.575 V

●

3.200 3.300 3.400 V

●

1.174 1.210 1.246 V

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

0.25 0.75 V

2.1 2.5 V

2.0 10 mV

2.5 10 mV

3.0 10 mV

3.5 10 mV

1.5 10 mV

18 mV

20 mV

30 mV

35 mV

15 mV

0.10 V

0.22 V

0.35 V

0.55 V

1.0 1.5 mA

1.1 1.6 mA

3.8 5.5 mA
15 25 mA
80 120 mA

0.90 2 V

RMS

1963fc

3

LT1963 Series

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. (Note 3)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Current Limit VIN = 7V, V

Input Reverse Leakage Current (Note 13) Q, T, S8 Packages VIN = – 20V, V

Reverse Output Current (Note 11) LT1963-1.5 V

Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.

Note 2: Absolute maximum input to output differential voltage can not be
achieved with all combinations of rated IN pin and OUT pin voltages. With
the IN pin at 20V, the OUT pin may not be pulled below 0V. The total
measured voltage from IN to OUT can not exceed ±20V.

Note 3: The LT1963 regulators are tested and specified under pulse load
conditions such that T

= 25°C. Performance at –40°C and 125°C is assured by design,

T

A

characterization and correlation with statistical process controls.
Note 4: The LT1963 (adjustable version) is tested and specified for these

conditions with the ADJ pin connected to the OUT pin.
Note 5: Operating conditions are limited by maximum junction

temperature. The regulated output voltage specification will not apply for
all possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range must be
limited. When operating at maximum output current, the input voltage
range must be limited.

Note 6: To satisfy requirements for minimum input voltage, the LT1963
(adjustable version) is tested and specified for these conditions with an

≈ TA. The LT1963 is 100% tested at

J

= V

V

IN

ST Package V

LT1963-1.8 V
LT1963-2.5 V
LT1963-3.3 V
LT1963 (Note 4) V

= 0V 2 A

OUT

OUT(NOMINAL)

+ 1V, ∆V

IN

= 1.5V, VIN < 1.5V 600 1200 µA

OUT

= 1.8V, VIN < 1.8V 600 1200 µA

OUT

= 2.5V, VIN < 2.5V 600 1200 µA

OUT

= 3.3V, VIN < 3.3V 600 1200 µA

OUT

= 1.21V, VIN < 1.21V 300 600 µA

OUT

= – 0.1V

OUT

OUT

= –20V, V

●

1.6 A

= 0V

= 0V

OUT

external resistor divider (two 4.12k resistors) for an output voltage of

2.4V. The external resistor divider will add a 300µA DC load on the output.
Note 7: Dropout voltage is the minimum input to output voltage differential

needed to maintain regulation at a specified output current. In dropout, the
output voltage will be equal to: V

Note 8: GND pin current is tested with V
current source load. The GND pin current will decrease at higher input
voltages.

Note 9: ADJ pin bias current flows into the ADJ pin.
Note 10: SHDN pin current flows into the SHDN pin.
Note 11: Reverse output current is tested with the IN pin grounded and the

OUT pin forced to the rated output voltage. This current flows into the OUT
pin and out the GND pin.

Note 12. For the LT1963, LT1963-1.5 and LT1963-1.8 dropout voltage will
be limited by the minimum input voltage specification under some output
voltage/load conditions.

Note 13. For the ST package, the input reverse leakage current increases
due to the additional reverse leakage current for the SHDN pin, which is
tied internally to the IN pin.

●

●

IN

– V

DROPOUT

= V

IN

.

OUT(NOMINAL)

1mA
2mA

+ 1V and a

4

1963fc

TEMPERATURE (°C)

–50

ADJ PIN VOLTAGE (V)

100

1963 G08

050

1.230

1.225

1.220

1.215

1.210

1.205

1.200

1.195

1.190
–25 25 75 125

IL = 1mA

UW

TEMPERATURE (°C)

–50

DROPOUT VOLTAGE (mV)

500

450

400

350

300

250

200

150

100

50

0

0

50

75

1963 G03

–25

25

100

125

IL = 100mA

IL = 1mA

IL = 0.5A

IL = 1.5A

TYPICAL PERFOR A CE CHARACTERISTICS

LT1963 Series

Typical Dropout Voltage Guaranteed Dropout Voltage

500

450

400

350

300

250

200

150

DROPOUT VOLTAGE (mV)

100

50

0

0

0.2 0.6

TJ = 125°C

TJ = 25°C

0.4

0.8

OUTPUT CURRENT (A)

1.0

1.2

1.4

1963 • G01

1.6

Quiescent Current LT1963-1.8 Output Voltage

1.4

1.2

LT1963-1.5/-1.8/-2.5/-3.3

1.0

0.8

0.6

0.4

QUIESCENT CURRENT (mA)

VIN = 6V

0.2

= ∞, IL = 0

R

L

= V

V

SHDN

0

–50

IN

–25 0

TEMPERATURE (°C)

LT1963

50 100 125

25 75

1963 G04

600

TEST POINTS

500

400

300

200

100

GUARANTEED DROPOUT VOLTAGE (mV)

0

0

0.2 0.6

TJ ≤ 125°C

0.4

0.8

OUTPUT CURRENT (A)

1.0

LT1963-1.5 Output Voltage

1.54
IL = 1mA

1.53

1.52

1.51

1.50

1.49

OUTPUT VOLTAGE (V)

1.48

1.47

1.46

–50

050

–25 25 75 125

TEMPERATURE (°C)

TJ ≤ 25°C

1.2

1.4

100

1.6

1963 • G02

1963 G04i

Dropout Voltage

1.84
IL = 1mA

1.83

1.82

1.81

1.80

1.79

OUTPUT VOLTAGE (V)

1.78

1.77

1.76

–25 25 75 125

–50

050

TEMPERATURE (°C)

100

1963 G05

LT1963-2.5 Output Voltage

2.58
IL = 1mA

2.56

2.54

2.52

2.50

2.48

OUTPUT VOLTAGE (V)

2.46

2.44

2.42

–50

050

–25 25 75 125

TEMPERATURE (°C)

100

1963 G06

LT1963-3.3 Output Voltage

3.38
IL = 1mA

3.36

3.34

3.32

3.30

3.28

OUTPUT VOLTAGE (V)

3.26

3.24

3.22

–50

050

–25 25 75 125

TEMPERATURE (°C)

LT1963 ADJ Pin Voltage

100

1963 G07

1963fc

5

LT1963 Series

UW

TYPICAL PERFOR A CE CHARACTERISTICS

LT1963-1.5 Quiescent Current

14

TJ = 25°C

= ∞

R

L

12

10

QUIESCENT CURRENT (mA)

= V

V

SHDN

IN

8

6

4

2

0

0

2

1

34
INPUT VOLTAGE (V)

LT1963-3.3 Quiescent Current

14

12

10

8

TJ = 25°C

= ∞

R

L

= V

V

SHDN

1963 G08i

LT1963-1.8 Quiescent Current LT1963-2.5 Quiescent Current

14

12

10

8

6

4

QUIESCENT CURRENT (mA)

2

0

1098765

0

2

1

34
INPUT VOLTAGE (V)

TJ = 25°C

= ∞

R

L

= V

V

SHDN

IN

5678910

1963 G09

LT1963 Quiescent Current

1.4

IN

1.2

1.0

0.8

TJ = 25°C

= 4.3k

R

L

= V

V

SHDN

IN

14

12

10

8

6

4

QUIESCENT CURRENT (mA)

2

0

0

2

1

34
INPUT VOLTAGE (V)

LT1963-1.5 GND Pin Current

25

TJ = 25°C

= V

V

SHDN

IN

*FOR V

20

15

OUT

= 1.5V

TJ = 25°C

= ∞

R

L

= V

V

SHDN

IN

1056789

1963 G10

6

4

QUIESCENT CURRENT (mA)

2

0

0

2

1

34
INPUT VOLTAGE (V)

1056789

1963 G11

0.6

0.4

QUIESCENT CURRENT (mA)

0.2

0

0

4

2

68
INPUT VOLTAGE (V)

1963 G12

10

GND PIN CURRENT (mA)

5

0

0

2010 12 14 16 18

19

RL = 5, IL = 300mA*

RL = 15, IL = 100mA*

RL = 150, IL = 10mA*

2

3

4

INPUT VOLTAGE (V)

5

LT1963-1.8 GND Pin Current LT1963-2.5 GND Pin Current LT1963-3.3 GND Pin Current

25

TJ = 25°C

= V

V

SHDN

IN

*FOR V

20

15

10

GND PIN CURRENT (mA)

5

0

0

= 1.8V

OUT

RL = 18, IL = 100mA*

RL = 180, IL = 10mA*

1

3

2

INPUT VOLTAGE (V)

RL = 6, IL = 300mA*

4

1963 G13

GND PIN CURRENT (mA)

1098765

25

20

15

10

5

0

0

RL = 8.33, IL = 300mA*

RL = 25, IL = 100mA*

RL = 250, IL = 10mA*

1

3

2

INPUT VOLTAGE (V)

TJ = 25°C

= V

V

SHDN

IN

*FOR V

4

OUT

= 2.5V

1963 G14

1098765

25

20

15

10

GND PIN CURRENT (mA)

5

0

0

RL = 330, IL = 100mA*

1

3

2

INPUT VOLTAGE (V)

RL = 11, IL = 300mA*

RL = 33, IL = 100mA*

4

6

7

TJ = 25°C

= V

V

SHDN

*FOR V

OUT

8

IN

= 3.3V

10

LT1963 G12i

1098765

1963 G15

1963fc

6

UW

INPUT VOLTAGE (V)

100

90

80

70

60

50

40

30

20

10

0

GND PIN CURRENT (mA)

1963 G17

0123

4

5

678910

RL = 1.8, IL = 1A*

RL = 1.2, IL = 1.5A*

RL = 3.6, IL = 500mA*

TJ = 25°C
V

SHDN

= V

IN

*FOR V

OUT

= 1.8V

TYPICAL PERFOR A CE CHARACTERISTICS

LT1963 Series

LT1963 GND Pin Current LT1963-1.8 GND Pin Current

10

8

6

4

GND PIN CURRENT (mA)

2

0

0

RL = 4.33, IL = 300mA*

RL = 12.1, IL = 100mA*

RL = 121, IL = 10mA*

1

3

2

INPUT VOLTAGE (V)

TJ = 25°C

= V

V

SHDN

IN

*FOR V

4

OUT

= 1.21V

1963 G16

1098765

LT1963-1.5 GND Pin Current

100

90

80

70

60

50

40

30

GND PIN CURRENT (mA)

20

10

0

2

0

3

19

INPUT VOLTAGE (V)

RL = 1, IL = 1.5A*

RL = 1.5, IL = 1A*

RL = 3, IL = 500mA*

4

5

TJ = 25°C

= V

V

SHDN

*FOR V

6

7

OUT

IN

= 1.5V

8

10

1963 G16i

LT1963-2.5 GND Pin Current LT1963-3.3 GND Pin Current LT1963 GND Pin Current

100

90

80

70

60

50

40

30

GND PIN CURRENT (mA)

20

10

0

0123

RL = 1.67, IL = 1.5A*

RL = 2.5, IL = 1A*

RL = 5, IL = 500mA*

INPUT VOLTAGE (V)

TJ = 25°C
V

SHDN

*FOR V

4

678910

5

= V

OUT

IN

= 2.5V

1963 G18

100

90

80

70

60

50

40

30

GND PIN CURRENT (mA)

20

10

0

0123

RL = 6.6, IL = 500mA*

INPUT VOLTAGE (V)

TJ = 25°C
V

SHDN

*FOR V

RL = 2.2, IL = 1.5A*

RL = 3.3, IL = 1A*

4

678910

5

= V

OUT

IN

= 3.3V

1963 G19

100

90

80

70

60

50

40

30

GND PIN CURRENT (mA)

20

10

0

0123

RL = 0.81, IL = 1.5A*

RL = 1.21, IL = 1A*

RL = 2.42, IL = 500mA*

INPUT VOLTAGE (V)

4

5

TJ = 25°C

= V

V

SHDN

IN

*FOR V

= 1.21V

OUT

678910

1963 G20

GND Pin Current vs I

100

90

80

70

60

50

40

30

GND PIN CURRENT (mA)

20

10

0

0 0.2 0.4 0.6

V

IN = VOUT (NOMINAL)

OUTPUT CURRENT (A)

0.8

+1V

LOAD

1.0

1.2 1.4 1.6

1963 G21

SHDN Pin Threshold (On-to-Off)

1.0
IL = 1mA

0.9

0.8

0.7

0.6

0.5

0.4

0.3

SHDN PIN THRESHOLD (V)

0.2

0.1

0

–50

0

–25

TEMPERATURE (°C)

50

25

SHDN Pin Threshold (Off-to-On)

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

SHDN PIN THRESHOLD (V)

0.2

0.1

100

125

1963 G22

75

0

–50

–25

IL = 1.5A

50

25

0

TEMPERATURE (°C)

IL = 1mA

75

100

125

1963 G23

1963fc

7

LT1963 Series

TEMPERATURE (°C)

–50

76

74

72

70

68

66

64

62

25 75

1963 G32

–25 0

50 100 125

RIPPLE REJECTION (dB)

IL = 0.75A
V

IN

= V

OUT(NOMINAL)

+1V + 0.5V

P-P

RIPPLE AT f = 120Hz

TEMPERATURE (°C)

–50

ADJ PIN BIAS CURRENT (µA)

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

0

50

75

1963 G26

–25

25

100

125

OUTPUT VOLTAGE (V)

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

REVERSE OUTPUT CURRENT (mA)

1963 G29

0123

4

5

678910

LT1963

LT1963-1.8

LT1963-1.5

LT1963-3.3

LT1963-2.5

CURRENT FLOWS INTO OUTPUT PIN
V

OUT

= V

ADJ

(LT1963)

V

OUT

= V

FB

(LT1963-1.5/-1.8/-2.5/-3.3)

TJ = 25°C
V

IN

= 0V

UW

TYPICAL PERFOR A CE CHARACTERISTICS

SHDN Pin Input Current

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

SHDN PIN INPUT CURRENT (µA)

0.5

0

0246

8

12 14 16 18 20

10

SHDN PIN VOLTAGE (V)

Current Limit

3.0

2.5
TJ = 25°C

2.0

TJ = 125°C

1.5

1.0

CURRENT LIMIT (A)

0.5

∆V

= 100mV

OUT

0

02 6 10 14 18

4 8 12 16

INPUT/OUTPUT DIFFERENTIAL (V)

TJ = –50°C

1963 G24

1963 G27

SHDN Pin Input Current

7

6

5

4

3

2

SHDN PIN INPUT CURRENT (µA)

1

0

–50

–25 0

25 75

TEMPERATURE (°C)

V

= 20V

SHDN

50 100 125

1963 G25

Current Limit

4.0
VIN = 7V

= 0V

V

OUT

3.5

3.0

2.5

2.0

1.5

CURRENT LIMIT (A)

1.0

0.5

0

20

–50

–25

0

TEMPERATURE (°C)

50

25

75

100

125

1963 G28

ADJ Pin Bias Current

Reverse Output Current

Reverse Output Current Ripple Rejection

1.0
VIN = 0V

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

REVERSE OUTPUT CURRENT (mA)

0.1

8

= 1.21V (LT1963)

V

OUT

= 1.5V (LT1963-1.5)

V

OUT

= 1.8V (LT1963-1.8)

V

OUT

= 2.5V (LT1963-2.5)

V

OUT

= 3.3V (LT1963-3.3)

V

OUT

0

–50

–25

LT1963-1.5/-1.8/-2.5/-3.3

LT1963

50

25

0

TEMPERATURE (°C)

75

100

1963 G30

125

80

70

60

50

40

30

RIPPLE REJECTION (dB)

20

10

0

C

= 100µF TANTALUM

OUT

+10 × 1µF CERAMIC

C

= 10µF TANTALUM

OUT

IL = 0.75A

= V

V

IN

OUT(NOMINAL)

10 1k 10k 1M

100 100k

+1V + 50mV

FREQUENCY (Hz)

RMS

Ripple Rejection

RIPPLE

1963 G31

1963fc

UW

TYPICAL PERFOR A CE CHARACTERISTICS

LT1963 Series

LT1963 Minimum Input Voltage

3.0

2.5

2.0

1.5

1.0

MINIMUM INPUT VOLTAGE (V)

0.5

0

–50

IL = 1.5A

–25 0

IL = 100mA

50 100 125

25 75

TEMPERATURE (°C)

RMS Output Noise vs Load
Current (10Hz to 100kHz)

50

C

= 10µF

OUT

45

)

40

RMS

35

30

25

20

15

10

OUTPUT NOISE VOLTAGE (µV

5

0

0.0001 0.01 0.1 10

0.001 1

IL = 500mA

1963 G33

LT1963-3.3

LT1963-2.5

LT1963-1.8

LT1963-1.5

LT1963

LOAD CURRENT (A)

Load Regulation

10

5

0

–5

–10

LOAD REGULATION (mV)

VIN = V

OUT(NOMINAL)

(LT1963-1.5/-1.8/-2.5/-3.3)

–15

= 2.7V (LT1963)

V

IN

= 1mA TO 1.5A

∆I

L

–20

–50

–25 0

TEMPERATURE (°C)

1063 G36

LT1963-1.5

LT1963-1.8

LT1963-2.5

LT1963-3.3

+1V

50 100 125

25 75

V

OUT

100µV/DIV

Output Noise Spectral Density

1.0

C

= 10µF

OUT

=1.5A

I

L

LT1963

1963 G34

OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz)

0.1

0.01

LT1963-3.3

10

LT1963-1.8

100 10k

LT1963-2.5

LT1963-1.5

1k 100k

FREQUENCY (Hz)

LT1963-3.3 10Hz to 100kHz Output Noise

C
I

LOAD

OUT

= 10µF

= 1.5A

1ms/DIV

LT1963

1963 G35

1963 G37

LT1963-3.3 Transient Response

200

VIN = 4.3V

= 3.3µF TANTALUM

C

150

IN

= 10µF TANTALUM

C

OUT

100

50

0

DEVIATION (mV)

OUTPUT VOLTAGE

–50

–100

0.6

0.4

LOAD

0.2

CURRENT (A)

0

0246

8

10

TIME (µs)

12 14 16 18 20

1963 G38

LT1963-3.3 Transient Response

150

100

50

0

–50

DEVIATION (mV)

OUTPUT VOLTAGE

–100

–150

1.5

1.0

0.5

LOAD

CURRENT (A)

0

0 50 100 150

VIN = 4.3V

= 33µF TANTALUM

C

IN

= 100µF TANTALUM

C

OUT

+10 × 1µF CERAMIC

250

300

TIME (µs)

350 400 450 500200

1963 G39

1963fc

9

LT1963 Series

U

UU

PI FU CTIO S

OUT: Output. The output supplies power to the load. A
minimum output capacitor of 10µF is required to prevent
oscillations. Larger output capacitors will be
required for applications with large transient loads to limit
peak voltage transients. See the Applications Information
section for more information on output capacitance and
reverse output characteristics.

SENSE: Sense. For fixed voltage versions of the LT1963
(LT1963-1.5/LT1963-1.8/LT1963-2.5/LT1963-3.3), the
SENSE pin is the input to the error amplifier. Optimum
regulation will be obtained at the point where the SENSE
pin is connected to the OUT pin of the regulator. In critical
applications, small voltage drops are caused by the resis­tance (RP) of PC traces between the regulator and the load.
These may be eliminated by connecting the SENSE pin to
the output at the load as shown in Figure 1 (Kelvin Sense
Connection). Note that the voltage drop across the exter­nal PC traces will add to the dropout voltage of the regu­lator. The SENSE pin bias current is 600µA at the nominal
rated output voltage. The SENSE pin can be pulled below
ground (as in a dual supply system where the regulator
load is returned to a negative supply) and still allow the
device to start and operate.

IN

V

+

IN

SHDN

LT1963

GND

OUT

SENSE

R

P

+

R

P

LOAD

1963 F01

ADJ: Adjust. For the adjustable LT1963, this is the input to
the error amplifier. This pin is internally clamped to ± 7V.
It has a bias current of 3µA which flows into the pin. The
ADJ pin voltage is 1.21V referenced to ground and the
output voltage range is 1.21V to 20V.

SHDN: Shutdown. The SHDN pin is used to put the LT1963
regulators into a low power shutdown state. The output
will be off when the SHDN pin is pulled low. The SHDN pin
can be driven either by 5V logic or open-collector logic
with a pull-up resistor. The pull-up resistor is required to
supply the pull-up current of the open-collector gate,
normally several microamperes, and the SHDN pin cur­rent, typically 3µA. If unused, the SHDN pin must be
connected to VIN. The device will be in the low power
shutdown state if the SHDN pin is not connected.

IN: Input. Power is supplied to the device through the IN
pin. A bypass capacitor is required on this pin if the device
is more than six inches away from the main input filter
capacitor. In general, the output impedance of a battery
rises with frequency, so it is advisable to include a bypass
capacitor in battery-powered circuits. A bypass capacitor
in the range of 1µF to 10µF is sufficient. The LT1963 regu-
lators are designed to withstand reverse voltages on the IN
pin with respect to ground and the OUT pin. In the case of
a reverse input, which can happen if a battery is plugged
in backwards, the device will act as if there is a diode in
series with its input. There will be no reverse current flow
into the regulator and no reverse voltage will appear at the
load. The device will protect both itself and the load.

Exposed Pad: GND. The Exposed Pad (FE Package) is
ground and must be soldered to the PCB for rated thermal
performance.Figure 1. Kelvin Sense Connection

10

1963fc

WUUU

APPLICATIO S I FOR ATIO

LT1963 Series

The LT1963 series are 1.5A low dropout regulators opti­mized for fast transient response. The devices are capable
of supplying 1.5A at a dropout voltage of 350mV. The low
operating quiescent current (1mA) drops to less than 1µA
in shutdown. In addition to the low quiescent current, the
LT1963 regulators incorporate several protection features
which make them ideal for use in battery-powered sys­tems. The devices are protected against both reverse input
and reverse output voltages. In battery backup applica­tions where the output can be held up by a backup battery
when the input is pulled to ground, the LT1963-X acts like
it has a diode in series with its output and prevents reverse
current flow. Additionally, in dual supply applications
where the regulator load is returned to a negative supply,
the output can be pulled below ground by as much as 20V
and still allow the device to start and operate.

Adjustable Operation

The adjustable version of the LT1963 has an output
voltage range of 1.21V to 20V. The output voltage is set by
the ratio of two external resistors as shown in Figure 2. The
device servos the output to maintain the voltage at the ADJ
pin at 1.21V referenced to ground. The current in R1 is
then equal to 1.21V/R1 and the current in R2 is the current
in R1 plus the ADJ pin bias current. The ADJ pin bias
current, 3µA at 25°C, flows through R2 into the ADJ pin.
The output voltage can be calculated using the formula in
Figure 2. The value of R1 should be less than 4.17k to
minimize errors in the output voltage caused by the ADJ
pin bias current. Note that in shutdown the output is turned
off and the divider current will be zero.

IN

V

IN

VV

OUT ADJ

VV

ADJ

IA

ADJ

OUTPUT RANGE = 1.21V TO 20V

Figure 2. Adjustable Operation

OUT

LT1963

ADJ

GND

⎛

=+

121 1

.

⎜
⎝

=

121

.

=°

3

µ AT 25 C

R2

R

2

⎞

+

()()

⎟
⎠

R

1

R1

IR

V

OUT

+

1963 F02

2

The adjustable device is tested and specified with the ADJ
pin tied to the OUT pin for an output voltage of 1.21V.
Specifications for output voltages greater than 1.21V will
be proportional to the ratio of the desired output voltage to

1.21V: V

/1.21V. For example, load regulation for an

OUT

output current change of 1mA to 1.5A is –3mV typical at
V

= 1.21V. At V

OUT

= 5V, load regulation is:

OUT

(5V/1.21V)(–3mV) = –12.4mV

Output Capacitance and Transient Response

The LT1963 regulators are designed to be stable with a wide
range of output capacitors. The ESR of the output capacitor
affects stability, most notably with small capacitors. A mini­mum output capacitor of 10µF with an ESR in the range of
50mΩ to 3Ω is recommended to prevent oscillations. Larger
values of output capacitance can decrease the peak devia­tions and provide improved transient response for larger
load current changes. Bypass capacitors, used to decouple
individual components powered by the LT1963, will in­crease the effective output capacitor value.

Extra consideration must be given to the use of ceramic
capacitors. Ceramic capacitors are manufactured with a
variety of dielectrics, each with different behavior across
temperature and applied voltage. The most common di­electrics used are specified with EIA temperature charac­teristic codes of Z5U, Y5V, X5R and X7R. The Z5U and Y5V
dielectrics are good for providing high capacitances in a
small package, but they tend to have strong voltage and
temperature coefficients as shown in Figures 2 and 3.
When used with a 5V regulator, a 16V 10µF Y5V capacitor
can exhibit an effective value as low as 1µF to 2µF for the
DC bias voltage applied and over the operating tempera­ture range. The X5R and X7R dielectrics result in more
stable characteristics and are more suitable for use as the
output capacitor. The X7R type has better stability across
temperature, while the X5R is less expensive and is
available in higher values. Care still must be exercised
when using X5R and X7R capacitors; the X5R and X7R
codes only specify operating temperature range and maxi­mum capacitance change over temperature. Capacitance
change due to DC bias with X5R and X7R capacitors is
better than Y5V and Z5U capacitors, but can still be
significant enough to drop capacitor values below appro­priate levels. Capacitor DC bias characteristics tend to

1963fc

11

LT1963 Series

WUUU

APPLICATIO S I FOR ATIO

20

0

–20

–40

–60

CHANGE IN VALUE (%)

–80

–100

0

Figure 3. Ceramic Capacitor DC Bias Characteristics

40

20

0

–20

–40

–60

CHANGE IN VALUE (%)

–80

BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10µF

–100

–50

BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10µF

X5R

Y5V

26

4

–25 0

8

DC BIAS VOLTAGE (V)

25 75

TEMPERATURE (°C)

14

12

10

Y5V

50 100 125

16

1963 F03

X5R

1963 F04

operating region for all values of input-to-output voltage.
The protection is designed to provide some output current
at all values of input-to-output voltage up to the device
breakdown.

When power is first turned on, as the input voltage rises,
the output follows the input, allowing the regulator to start
up into very heavy loads. During the start-up, as the input
voltage is rising, the input-to-output voltage differential is
small, allowing the regulator to supply large output
currents. With a high input voltage, a problem can occur
wherein removal of an output short will not allow the
output voltage to recover. Other regulators, such as the
LT1085, also exhibit this phenomenon, so it is not unique
to the LT1963-X.

The problem occurs with a heavy output load when the
input voltage is high and the output voltage is low. Com­mon situations are immediately after the removal of a
short-circuit or when the shutdown pin is pulled high after
the input voltage has already been turned on. The load line
for such a load may intersect the output current curve at
two points. If this happens, there are two stable output
operating points for the regulator. With this double inter­section, the input power supply may need to be cycled down
to zero and brought up again to make the output recover.

Output Voltage Noise

Figure 4. Ceramic Capacitor Temperature Characteristics

improve as component case size increases, but expected
capacitance at operating voltage should be verified.

Voltage and temperature coefficients are not the only
sources of problems. Some ceramic capacitors have a
piezoelectric response. A piezoelectric device generates
voltage across its terminals due to mechanical stress,
similar to the way a piezoelectric accelerometer or micro­phone works. For a ceramic capacitor the stress can be
induced by vibrations in the system or thermal transients.

Overload Recovery

Like many IC power regulators, the LT1963-X has safe
operating area protection. The safe area protection de­creases the current limit as input-to-output voltage in­creases and keeps the power transistor inside a safe

12

The LT1963 regulators have been designed to provide low
output voltage noise over the 10Hz to 100kHz bandwidth
while operating at full load. Output voltage noise is typi­cally 40nV/√Hz over this frequency bandwidth for the
LT1963 (adjustable version). For higher output voltages
(generated by using a resistor divider), the output voltage
noise will be gained up accordingly. This results in RMS
noise over the 10Hz to 100kHz bandwidth of 14µV
the LT1963 increasing to 38µV

for the LT1963-3.3.

RMS

RMS

for

Higher values of output voltage noise may be measured
when care is not exercised with regards to circuit layout
and testing. Crosstalk from nearby traces can induce
unwanted noise onto the output of the LT1963-X. Power
supply ripple rejection must also be considered; the LT1963
regulators do not have unlimited power supply rejection
and will pass a small portion of the input noise through to
the output.

1963fc

WUUU

APPLICATIO S I FOR ATIO

LT1963 Series

Thermal Considerations

The power handling capability of the device is limited by the
maximum rated junction temperature (125°C). The power
dissipated by the device is made up of two components:

1. Output current multiplied by the input/output voltage
differential: (I

)(VIN – V

OUT

OUT

), and

2. GND pin current multiplied by the input voltage:
(I

)(VIN).

GND

The GND pin current can be found using the GND Pin
Current curves in the Typical Performance Characteris­tics. Power dissipation will be equal to the sum of the two
components listed above.

The LT1963 series regulators have internal thermal lim­iting designed to protect the device during overload
conditions. For continuous normal conditions, the maxi­mum junction temperature rating of 125°C must not be
exceeded. It is important to give careful consideration to
all sources of thermal resistance from junction to ambi­ent. Additional heat sources mounted nearby must also
be considered.

For surface mount devices, heat sinking is accomplished
by using the heat spreading capabilities of the PC board
and its copper traces. Copper board stiffeners and plated
through-holes can also be used to spread the heat gener­ated by power devices.

The following tables list thermal resistance for several
different board sizes and copper areas. All measurements
were taken in still air on 1/16" FR-4 board with one ounce
copper.

Table 1. Q Package, 5-Lead DD

COPPER AREA

TOPSIDE* BACKSIDE

2500mm22500mm

1000mm22500mm

125mm22500mm

*

Device is mounted on topside

BOARD AREA (JUNCTION-TO-AMBIENT)

2

2500mm

2

2500mm

2

2500mm

THERMAL RESISTANCE

2

2

2

23°C/W

25°C/W

33°C/W

Table 2. SO-8 Package, 8-Lead SO

COPPER AREA

TOPSIDE* BACKSIDE

2500mm22500mm22500mm

1000mm22500mm22500mm

2

225mm

100mm

*

Device is mounted on topside

2500mm22500mm

2

2500mm22500mm

BOARD AREA (JUNCTION-TO-AMBIENT)

THERMAL RESISTANCE

2

2

2

2

55°C/W

55°C/W

63°C/W

69°C/W

Table 3. SOT-223 Package, 3-Lead SOT-223

COPPER AREA

TOPSIDE* BACKSIDE

2500mm22500mm22500mm

1000mm22500mm22500mm

2

225mm

100mm

1000mm21000mm21000mm

1000mm

*

Device is mounted on topside

2500mm22500mm

2

2500mm22500mm

2

0mm

BOARD AREA (JUNCTION-TO-AMBIENT)

2

1000mm

THERMAL RESISTANCE

2

2

2

2

2

2

42°C/W

42°C/W

50°C/W

56°C/W

49°C/W

52°C/W

Table 4. FE Package, 16-Lead TSSOP

COPPER AREA

TOPSIDE* BACKSIDE

2500mm22500mm22500mm

1000mm22500mm22500mm

2

225mm

100mm

*

Device is mounted on topside

2500mm22500mm

2

2500mm22500mm

BOARD AREA (JUNCTION-TO-AMBIENT)

THERMAL RESISTANCE

2

2

2

2

38°C/W

43°C/W

48°C/W

60°C/W

T Package, 5-Lead TO-220

Thermal Resistance (Junction-to-Case) = 4°C/W

Calculating Junction Temperature

Example: Given an output voltage of 3.3V, an input voltage
range of 4V to 6V, an output current range of 0mA to
500mA and a maximum ambient temperature of 50°C,
what will the maximum junction temperature be?

The power dissipated by the device will be equal to:

I

OUT(MAX)(VIN(MAX)

– V

OUT

) + I

GND(VIN(MAX)

)

where,

I

OUT(MAX)

V

IN(MAX)

I

GND

at (I

= 500mA

= 6V

= 500mA, VIN = 6V) = 10mA

OUT

So,

P = 500mA(6V – 3.3V) + 10mA(6V) = 1.41W

1963fc

13

LT1963 Series

WUUU

APPLICATIO S I FOR ATIO

Using a DD package, the thermal resistance will be in the
range of 23°C/W to 33°C/W depending on the copper
area. So the junction temperature rise above ambient will
be approximately equal to:

1.41W(28°C/W) = 39.5°C

The maximum junction temperature will then be equal to
the maximum junction temperature rise above ambient
plus the maximum ambient temperature or:

T

= 50°C + 39.5°C = 89.5°C

JMAX

Protection Features

The LT1963 regulators incorporate several protection
features which make them ideal for use in battery-powered
circuits. In addition to the normal protection features
associated with monolithic regulators, such as current
limiting and thermal limiting, the devices are protected
against reverse input voltages, reverse output voltages
and reverse voltages from output to input.

Current limit protection and thermal overload protection
are intended to protect the device against current overload
conditions at the output of the device. For normal opera­tion, the junction temperature should not exceed 125°C.

The input of the device will withstand reverse voltages of
20V. Current flow into the device will be limited to less than
1mA (typically less than 100µA) and no negative voltage
will appear at the output. The device will protect both itself
and the load. This provides protection against batteries
that can be plugged in backward.

The output of the LT1963 can be pulled below ground
without damaging the device. If the input is left open circuit
or grounded, the output can be pulled below ground by
20V. For fixed voltage versions, the output will act like a
large resistor, typically 5k or higher, limiting current flow
to typically less than 600µA. For adjustable versions, the
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
output will source the short-circuit current of the device
and will protect itself by thermal limiting. In this case,
grounding the SHDN pin will turn off the device and stop
the output from sourcing the short-circuit current.

The ADJ pin of the adjustable device can be pulled above
or below ground by as much as 7V without damaging the

device. If the input is left open circuit or grounded, the ADJ
pin will act like an open circuit when pulled below ground
and like a large resistor (typically 5k) in series with a diode
when pulled above ground.

In situations where the ADJ pin is connected to a resistor
divider that would pull the ADJ pin above its 7V clamp
voltage if the output is pulled high, the ADJ pin input
current must be limited to less than 5mA. For example, a
resistor divider is used to provide a regulated 1.5V output
from the 1.21V reference when the output is forced to 20V.
The top resistor of the resistor divider must be chosen to
limit the current into the ADJ pin to less than 5mA when the
ADJ pin is at 7V. The 13V difference between OUT and ADJ
pins divided by the 5mA maximum current into the ADJ pin
yields a minimum top resistor value of 2.6k.

In circuits where a backup battery is required, several
different input/output conditions can occur. The output
voltage may be held up while the input is either pulled to
ground, pulled to some intermediate voltage, or is left
open circuit. Current flow back into the output will follow
the curve shown in Figure 5.

When the IN pin of the LT1963 is forced below the OUT pin
or the OUT pin is pulled above the IN pin, input current will
typically drop to less than 2µA. This can happen if the
input of the device is connected to a discharged (low
voltage) battery and the output is held up by either a
backup battery or a second regulator circuit. The state of
the SHDN pin will have no effect on the reverse output
current when the output is pulled above the input.

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

REVERSE OUTPUT CURRENT (mA)

0.5

0

0

Figure 5. Reverse Output Current

V

OUT

LT1963-1.5

V

OUT

LT1963-1.8

= V

V

OUT

LT1963-2.5

= V

V

OUT

213

LT1963
= V

ADJ

= V

FB

FB

FB

4

5

OUTPUT VOLTAGE (V)

LT1963-3.3

= V

V

OUT

TJ = 25°C

= 0V

V

IN

CURRENT FLOWS
INTO OUTPUT PIN

697

8

1963 F05

FB

10

1963fc

14

TYPICAL APPLICATIO S

SCR Pre-Regulator Provides Efficiency Over Line Variations

L2

10VAC AT

115V

90-140

VAC

IN

10VAC AT

115V

IN

U

1N4148

1k

L1

500µH

LT1963 Series

LT1963-3.3

IN

+

10000µF

34k*

SHDN

GND

OUT

FB

3.3V

OUT

1.5A

+

22µF

1N4002 1N4002

“SYNC”

1N4002

TO ALL “+V”

POINTS

22µF

V

+

> 3.7V

IN

12.1k*

0.1µF

+V

A1

LT1006

1µF

2.4k

+

750Ω

LT1018

–

0.033µF

L1 = COILTRONICS CTX500-2-52
L2 = STANCOR P-8559
* = 1% FILM RESISTOR
= NTE5437

1/2

+V

C1A

1N4148

+V

C1B

750Ω

1/2

LT1018

200k

+

1N4148

–

10k

+V

Paralleling of Regulators for Higher Output Current

R1

0.01Ω

+

C1
100µF

LT1963-3.3

IN

SHDN

GND

OUT

FB

+

10k

3.3V

3A
C2
22µF

10k

LT1004

1.2V

+V

1963 TA03

–

+

SHDN

R2

0.01Ω

R3

2.2kR42.2k

LT1963

IN

OUT

SHDN

3

+

2

–

GND

1/2

LT1366

FB

8

4

R6

6.65k

R7

4.12k

R5

1k

1

C3

0.01µF

1963 TA05

1963fc

15

LT1963 Series

PACKAGE DESCRIPTIO

U

Q Package

5-Lead Plastic DD Pak

(Reference LTC DWG # 05-08-1461)

.256

(6.502)

.060

(1.524)

.300

(7.620)

BOTTOM VIEW OF DD PAK

HATCHED AREA IS SOLDER PLATED

COPPER HEAT SINK

.060

(1.524)

.075

(1.905)

.183

(4.648)

.060

(1.524)

TYP

.330 – .370

(8.382 – 9.398)

+.012

.143

–.020

+0.305

3.632

()

–0.508

.420

.350

.028 – .038

(0.711 – 0.965)

.565

(9.906 – 10.541)

TYP

.080

.390 – .415

15° TYP

.067

(1.702)

BSC

.205

.165 – .180

(4.191 – 4.572)

.420
.276

.059

(1.499)

TYP

.013 – .023

(0.330 – 0.584)

.325

.045 – .055

(1.143 – 1.397)

+.008

.004

–.004
+0.203

0.102

()

–0.102

.095 – .115

(2.413 – 2.921)

.050 ± .012

(1.270 ± 0.305)

Q(DD5) 0502

.565

16

.067

RECOMMENDED SOLDER PAD LAYOUT

NOTE:

1. DIMENSIONS IN INCH/(MILLIMETER)

2. DRAWING NOT TO SCALE

.042

.090

.320

.090

.067

RECOMMENDED SOLDER PAD LAYOUT

FOR THICKER SOLDER PASTE APPLICATIONS

.042

1963fc

PACKAGE DESCRIPTIO

.050 BSC

U

S8 Package

8-Lead Plastic Small Outline (Narrow .150 Inch)

(Reference LTC DWG # 05-08-1610)

.189 – .197

.045 ±.005

(4.801 – 5.004)

8

NOTE 3

7

6

LT1963 Series

5

.245
MIN

.030 ±.005

TYP

RECOMMENDED SOLDER PAD LAYOUT

.010 – .020

(0.254 – 0.508)

.008 – .010

(0.203 – 0.254)

NOTE:

1. DIMENSIONS IN

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)

× 45°

.016 – .050

(0.406 – 1.270)

INCHES

(MILLIMETERS)

.160 ±.005

.228 – .244

(5.791 – 6.197)

0°– 8° TYP

.053 – .069

(1.346 – 1.752)

.014 – .019

(0.355 – 0.483)

TYP

.150 – .157

(3.810 – 3.988)

NOTE 3

1

3

2

4

.004 – .010

(0.101 – 0.254)

.050

(1.270)

BSC

SO8 0303

1963fc

17

LT1963 Series

PACKAGE DESCRIPTIO

U

ST Package

3-Lead Plastic SOT-223

(Reference LTC DWG # 05-08-1630)

.264 – .287

(6.70 – 7.30)

.130 – .146

(3.30 – 3.71)

.071

(1.80)

MAX

.0905

(2.30)

BSC

.248 – .264

(6.30 – 6.71)

.114 – .124

(2.90 – 3.15)

.024 – .033

(0.60 – 0.84)

.181

(4.60)

BSC

.033 – .041

(0.84 – 1.04)

.012

(0.31)

MIN

.059 MAX

10°

MAX

.129 MAX

.059 MAX

.181 MAX

RECOMMENDED SOLDER PAD LAYOUT

10° – 16°

.0008 – .0040

(0.0203 – 0.1016)

.039 MAX

10° – 16°

.248 BSC

.090
BSC

ST3 (SOT-233) 0502

.010 – .014

(0.25 – 0.36)

0.390 – 0.415

(9.906 – 10.541)

0.460 – 0.500

(11.684 – 12.700)

0.067

BSC

(1.70)

0.147 – 0.155

(3.734 – 3.937)

0.230 – 0.270

(5.842 – 6.858)

0.330 – 0.370

(8.382 – 9.398)

0.028 – 0.038

(0.711 – 0.965)

T Package

5-Lead Plastic TO-220 (Standard)

(Reference LTC DWG # 05-08-1421)

DIA

0.570 – 0.620

(14.478 – 15.748)

SEATING PLANE

0.152 – 0.202

0.260 – 0.320
(6.60 – 8.13)

(3.861 – 5.131)

0.165 – 0.180

(4.191 – 4.572)

0.700 – 0.728

(17.78 – 18.491)

0.135 – 0.165

(3.429 – 4.191)

0.620

(15.75)

TYP

0.045 – 0.055

(1.143 – 1.397)

0.095 – 0.115

(2.413 – 2.921)

0.155 – 0.195*

(3.937 – 4.953)

0.013 – 0.023

(0.330 – 0.584)

* MEASURED AT THE

SEATING PLANE

T5 (TO-220) 0399

1963fc

18

PACKAGE DESCRIPTIO

3.58

(.141)

U

FE Package

16-Lead Plastic TSSOP (4.4mm)

(Reference LTC DWG # 05-08-1663)

Exposed Pad Variation BB

4.90 – 5.10*
(.193 – .201)

3.58

(.141)

16 1514 13 12 11

LT1963 Series

10 9

6.60 ±0.10

4.50 ±0.10

RECOMMENDED SOLDER PAD LAYOUT

0.09 – 0.20

(.0035 – .0079)

NOTE:

1. CONTROLLING DIMENSION: MILLIMETERS

2. DIMENSIONS ARE IN

3. DRAWING NOT TO SCALE

SEE NOTE 4

0.65 BSC

4.30 – 4.50*
(.169 – .177)

0.50 – 0.75

(.020 – .030)

MILLIMETERS

(INCHES)

(.116)

0.45 ±0.05

2.94

1.05 ±0.10

1345678

2

0.25
REF

0° – 8°

0.65

(.0256)

BSC

0.195 – 0.30

(.0077 – .0118)

TYP

4. RECOMMENDED MINIMUM PCB METAL SIZE
FOR EXPOSED PAD ATTACHMENT

*DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.150mm (.006") PER SIDE

2.94

(.116)

1.10

(.0433)

MAX

0.05 – 0.15

(.002 – .006)

FE16 (BB) TSSOP 0204

6.40

(.252)

BSC

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen­tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

1963fc

19

LT1963 Series

TYPICAL APPLICATIO S

U

Adjustable Current Source

R5

0.01Ω

LT1004-1.2

80.6k

R3

2k

R1

1k

R2

3.3µF

R4

R6

2.2k

2.2k

2

+

LT1366

3

C2

–

+

VIN > 2.7V

NOTE: ADJUST R1 FOR
0A TO 1.5A CONSTANT CURRENT

C1

10µF

RELATED PARTS

PART NUMBER DESCRIPTION COMMENTS

LT1129 700mA, Micropower, LDO VIN: 4.2V to 30V, V

DD, SOT-223, S8, TO220, TSSOP20 Packages

LT1175 500mA, Micropower Negative LDO VIN: –20V to –4.3V, V

DD, SOT-223, S8 Packages

LT1185 3A, Negative LDO VIN: –35V to –4.2V, V

TO220-5 Package

LT1761 100mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, V

ThinSOT Package

LT1762 150mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, V

LT1763 500mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, V

LT1764/ 3A, Low Noise, Fast Transient Response, VIN: 2.7V to 20V, V
LT1764A LDO DD, TO220 Packages

LTC1844 150mA, Very Low Drop-Out LDO VIN: 6.5V to 1.6V, V

ThinSOT Package

LT1962 300mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, V

LT1963/ 1.5A, Low Noise, Fast Transient Response, VIN: 2.1V to 20V, V
LT1963A LDO DD, TO220, SOT Packages

LT1964 200mA, Low Noise Micropower, Negative VIN: –0.9V to –20V, V

LDO ThinSOT Package

LT3020 100mA, Low Voltage V

LDO

VIN: 0.9V to 10V, V
DFN, MS8 Packages

LT3023 Dual, 2x 100mA, Low Noise Micropower, VIN: 1.8V to 20V, V

LDO DFN, MS10 Packages

LT3024 Dual, 100mA/500mA, Low Noise Micropower, VIN: 1.8V to 20V, V

LDO DFN, TSSOP Package

LT3150 Fast Transient Response, Low Input Voltage VIN: –1.4V to 10V, V

GN16 Package

Linear Technology Corporation

20

1630 McCarthy Blvd., Milpitas, CA 95035-7417

[phone] ● FAX: [phone]

●

www.linear.com

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

OUT(MIN)

LT1963-1.8

IN

SHDN

GND

C3

1µF

8

1/2

4

OUT

1

LOAD

FB

R8
100k

R7
470Ω

1963 TA04

= 3.75V, VDO = 0.40V, IQ = 50µA, ISD = 16µA,

= –3.8V, VDO = 0.50V, IQ = 45µA, ISD = 10µA,

= –2.40V, VDO = 0.80V, IQ = 2.5mA, ISD <1µA,

= 1.22V, VDO = 0.30V, IQ = 20µA, ISD <1µA,

= 1.22V, VDO = 0.30V, IQ = 25µA, ISD <1µA, MS8 Package

= 1.22V, VDO = 0.30V, IQ = 30µA, ISD <1µA, S8 Package

= 1.21V, VDO = 0.34V, IQ = 1mA, ISD <1µA,

= 1.25V, VDO = 0.08V, IQ = 40µA, ISD <1µA,

= 1.22V, VDO = 0.27V, IQ = 30µA, ISD <1µA, MS8 Package

= 1.21V, VDO = 0.34V, IQ = 1mA, ISD <1µA,

= –1.21V, VDO = 0.34V, IQ = 30µA, ISD = 3µA,

= 0.20, VDO = 0.15V, IQ = 120µA, ISD <3µA,

= 1.22V, VDO = 0.30V, IQ = 40µA, ISD <1µA,

= 1.22V, VDO = 0.30V, IQ = 60µA, ISD <1µA,

= 1.23V, VDO = 0.13V, IQ = 12mA, ISD = 25µA,

LT 1105 • PRINTED IN USA

© LINEAR TECHNOLOGY CORPORATION 2005

1963fc