ANALOG DEVICES LT 1129 CST-3.3 Datasheet

LT1129/LT1129-3.3/LT1129-5

IN OUT

LT1129-5

GND

5V OUT
500mA

V

IN

> 5.5V

3.3μF
SOLID TANTALUM

+

SENSE

112935 TA01

V

SHDN

(PIN 4)

< 0.25

> 2.8

NC

OUTPUT

OFF

ON
ON

SHDN

1

2

3

4

5

Micropower Low Dropout

Regulators with Shutdown

FEATURES

n

400mV Dropout Voltage

n

700mA Output Current

n

50μA Quiescent Current

n

No Protection Diodes Needed

n

Adjustable Output from 3.8V to 30V

n

3.3V and 5V Fixed Output Voltages

n

Controlled Quiescent Current in Dropout

n

Shutdown

n

16μA Quiescent Current in Shutdown

n

Stable with 3.3μF Output Capacitor

n

Reverse Battery Protection

n

No Reverse Output Current

n

Thermal Limiting

n

Surface Mount SOT-223 and DD-Pak Packages

APPLICATIONS

n

Low Current Regulator

n

Regulator for Battery-Powered Systems

n

Post Regulator for Switching Supplies

n

5V to 3.3V Logic Regulator

DESCRIPTION

The LT®1129/LT1129-3.3/LT1129-5 are micropower low
dropout regulators with shutdown. The devices are capable
of supplying 700mA of output current with a dropout
voltage of 400mV at maximum output. Designed for use
in battery-powered systems, the low quiescent current,
50μA operating and 16μA in shutdown, make them an ideal
choice. The quiescent current does not rise in dropout as
it does with many other low dropout PNP regulators.

Other features of the LT1129 /LT1129-3.3/LT1129-5 include
the ability to operate with small output capacitors. They
are stable with only 3.3μF on the output while most older
devices require between 10μF and 100μF for stability. Also
the input may be connected to ground or a reverse voltage
without reverse current fl ow from output to input. This
makes the LT1129/LT1129-3.3/LT1129-5 ideal for backup
power situations where the output is held high and the
input is at ground or reversed. Under these conditions,
only 16μA will fl ow from the output pin to ground. The
devices are available in 5-lead TO-220, 5-lead DD-Pak and
3-lead SOT-223 packages.

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.

TYPICAL APPLICATION

5V Supply with Shutdown

Dropout Voltage

0.6

0.5

0.4

0.3

0.2

DROPOUT VOLTAGE (V)

0.1

0

0

0.1 0.2
OUTPUT CURRENT (A)

0.4 0.6 0.7

0.3 0.5

112935 TA02

112935ff

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LT1129/LT1129-3.3/LT1129-5

ABSOLUTE MAXIMUM RATINGS

Input Voltage ...................................................... ± 30V*

Output Pin Reverse Current ................................. 10mA

Sense Pin Current ................................................ 10mA

Adjust Pin Current ................................................ 10mA

Sense Pin, Adjust Pin Reverse Voltage ............... –0.6V

Shutdown Pin Input Voltage (Note 2) ......... 6.5V, – 0.6V

Shutdown Pin Input Current (Note 2) .................. 20mA

Output Short-Circuit Duration .......................... Indefi nite

PIN CONFIGURATION

TOP VIEW

1

GND

2

GND

3

GND

4

GND

5

GND

6

GND

7

OUT

8

SENSE

9

GND

10

GND

F PACKAGE

20-LEAD PLASTIC TSSOP

NOTE: ALL GROUND PINS ARE INTERNALLY CONNECTED

= 40°C/W

θ

JA

GND

20

GND

19

GND

18

GND

17

GND

16

GND

15

IN

14

SHDN

13

GND

12

GND

11

TAB

IS

GND

*PIN 2 = SENSE FOR LT1129-3.3/LT1129-5

(Note 1)

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

Operating Junction Temperature Range (Note 3)

LT1129C-X .......................................... 0°C to 125°C

LT1129C-X Extended Temperature Range

(Note 12) ....................................... –40°C to 125°C

LT1129I-X(Note 12) ......................... –40°C to 125°C

LT1129MP-X(Note 12) .....................–55°C to 125°C

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

* For applications requiring input voltage ratings greater than 30V, contact the factory.

FRONT VIEW

5

4

3

2

1

Q PACKAGE

5-LEAD PLASTIC DD

= ADJ FOR LT1129

= 30°C/W

θ

JA

V

IN

SHDN

GND

SENSE/ADJ*

OUTPUT

OUTPUT

SENSE/

*PIN 2 = SENSE FOR LT1129-3.3/LT1129-5

1

2

ADJ*

3

GND

NC

4

S8 PACKAGE

8-LEAD PLASTIC SO

= ADJ FOR LT1129

θ

JA

TOP VIEW

8

7

6

5

= 60°C/W

V

IN

GND

GND

SHDN

OBSOLETE PACKAGE

FRONT VIEW

TAB

IS

GND

ST PACKAGE

3-LEAD PLASTIC SOT-223

θJA = 50°C/W

3

2

1

OUTPUT

GND

V

IN

TAB

IS

GND

*PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 = ADJ FOR LT1129

FRONT VIEW

5

4

3

2

1

T PACKAGE

5-LEAD PLASTIC TO-220

= 50°C/W

θ

JA

V

IN

SHDN

GND

SENSE/ADJ*

OUTPUT

ORDER INFORMATION

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LT1129CS8#PBF LT1129CS8#TRPBF 1129 8-Lead Plastic SO 0°C to 125°C

LT1129IS8#PBF LT1129IS8#TRPBF 1129I 8-Lead Plastic SO –40°C to 125°C

LT1129CS8-3.3#PBF LT1129CS8-3.3#TRPBF 11293 8-Lead Plastic SO 0°C to 125°C

LT1129IS8-3.3#PBF LT1129IS8-3.3#TRPBF 1129I3 8-Lead Plastic SO –40°C to 125°C

LT1129CS8-5#PBF LT1129CS8-5#TRPBF 11295 8-Lead Plastic SO 0°C to 125°C

112935ff

2

LT1129/LT1129-3.3/LT1129-5

ORDER INFORMATION

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LT1129IS8-5#PBF LT1129IS8-5#TRPBF 1129I5 8-Lead Plastic SO –40°C to 125°C

LT1129CST-3.3#PBF LT1129CST-3.3#TRPBF 11293 3-Lead Plastic SOT-223 0°C to 125°C

LT1129IST-3.3#PBF LT1129IST-3.3#TRPBF 129I3 3-Lead Plastic SOT-223 –40°C to 125°C

LT1129MPST-3.3#PBF LT1129MPST-3.3#TRPBF 129MP3 3-Lead Plastic SOT-223 –55°C to 125°C

LT1129CST-5#PBF LT1129CST-5#TRPBF 11295 3-Lead Plastic SOT-223 0°C to 125°C

LT1129IST-5#PBF LT1129IST-5#TRPBF 129I5 3-Lead Plastic SOT-223 –40°C to 125°C

LT1129CQ#PBF LT1129CQ#TRPBF LT1129CQ 5-Lead Plastic DD-PAK 0°C to 125°C

LT1129IQ#PBF LT1129IQ#TRPBF LT1129IQ 5-Lead Plastic DD-PAK –40°C to 125°C

LT1129CQ-3.3#PBF LT1129CQ-3.3#TRPBF LT1129CQ-3.3 5-Lead Plastic DD-PAK 0°C to 125°C

LT1129IQ-3.3#PBF LT1129IQ-3.3#TRPBF LT1129IQ-3.3 5-Lead Plastic DD-PAK –40°C to 125°C

LT1129CQ-5#PBF LT1129CQ-5#TRPBF LT1129CQ-5 5-Lead Plastic DD-PAK 0°C to 125°C

LT1129IQ-5#PBF LT1129IQ-5#TRPBF LT1129IQ-5 5-Lead Plastic DD-PAK –40°C to 125°C

LT1129CT#PBF LT1129CT#TRPBF LT1129CT 5-Lead Plastic TO-220 0°C to 125°C

LT1129IT#PBF LT1129IT#TRPBF LT1129IT 5-Lead Plastic TO-220 –40°C to 125°C

LT1129CT-3.3#PBF LT1129CT-3.3#TRPBF LT1129CT-3.3 5-Lead Plastic TO-220 0°C to 125°C

LT1129IT-3.3#PBF LT1129IT-3.3#TRPBF LT1129IT-3.3 5-Lead Plastic TO-220 –40°C to 125°C

LT1129CT-5#PBF LT1129CT-5#TRPBF LT1129CT-5 5-Lead Plastic TO-220 0°C to 125°C

LT1129IT-5#PBF LT1129IT-5#TRPBF LT1129IT-5 5-Lead Plastic TO-220 –40°C to 125°C

LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LT1129CS8 LT1129CS8#TR 1129 8-Lead Plastic SO 0°C to 125°C

LT1129IS8 LT1129IS8#TR 1129I 8-Lead Plastic SO –40°C to 125°C

LT1129CS8-3.3 LT1129CS8-3.3#TR 11293 8-Lead Plastic SO 0°C to 125°C

LT1129IS8-3.3 LT1129IS8-3.3#TR 1129I3 8-Lead Plastic SO –40°C to 125°C

LT1129CS8-5 LT1129CS8-5#TR 11295 8-Lead Plastic SO 0°C to 125°C

LT1129IS8-5 LT1129IS8-5#TR 1129I5 8-Lead Plastic SO –40°C to 125°C

LT1129CST-3.3 LT1129CST-3.3#TR 11293 3-Lead Plastic SOT-223 0°C to 125°C

LT1129IST-3.3 LT1129IST-3.3#TR 129I3 3-Lead Plastic SOT-223 –40°C to 125°C

LT1129MPST-3.3 LT1129MPST-3.3#TR 129MP3 3-Lead Plastic SOT-223 –55°C to 125°C

LT1129CST-5 LT1129CST-5#TR 11295 3-Lead Plastic SOT-223 0°C to 125°C

LT1129IST-5 LT1129IST-5#TR 129I5 3-Lead Plastic SOT-223 –40°C to 125°C

LT1129CQ LT1129CQ#TR LT1129CQ 5-Lead Plastic DD-PAK 0°C to 125°C

LT1129IQ LT1129IQ#TR LT1129IQ 5-Lead Plastic DD-PAK –40°C to 125°C

LT1129CQ-3.3 LT1129CQ-3.3#TR LT1129CQ-3.3 5-Lead Plastic DD-PAK 0°C to 125°C

LT1129IQ-3.3 LT1129IQ-3.3#TR LT1129IQ-3.3 5-Lead Plastic DD-PAK –40°C to 125°C

LT1129CQ-5 LT1129CQ-5#TR LT1129CQ-5 5-Lead Plastic DD-PAK 0°C to 125°C

LT1129IQ-5 LT1129IQ-5#TR LT1129IQ-5 5-Lead Plastic DD-PAK –40°C to 125°C

LT1129CT LT1129CT#TR LT1129CT 5-Lead Plastic TO-220 0°C to 125°C

LT1129IT LT1129IT#TR LT1129IT 5-Lead Plastic TO-220 –40°C to 125°C

LT1129CT-3.3 LT1129CT-3.3#TR LT1129CT-3.3 5-Lead Plastic TO-220 0°C to 125°C

LT1129IT-3.3 LT1129IT-3.3#TR LT1129IT-3.3 5-Lead Plastic TO-220 –40°C to 125°C

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LT1129/LT1129-3.3/LT1129-5

ORDER INFORMATION

LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LT1129CT-5 LT1129CT-5#TR LT1129CT-5 5-Lead Plastic TO-220 0°C to 125°C

LT1129IT-5 LT1129IT-5#TR LT1129IT-5 5-Lead Plastic TO-220 –40°C to 125°C

Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/

For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/

The l denotes the specifi cations which apply over the full operating

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifi cations are at TA = 25°C.

SYMBOL CONDITIONS MIN TYP MAX UNITS

Regulated Output Voltage
(Notes 4, 12)

Line Regulation (Note 12)

Load Regulation (Note 12)

Dropout Voltage
(Note 6)

Ground Pin Current
(Note 7)

Adjust Pin Bias Current (Notes 5, 8) T

Shutdown Threshold V

Shutdown Pin Current (Note 9) V

Quiescent Current in Shutdown
(Note 10)

LT1129-3.3 V

= 3.8V, I

IN

4.3V < V

LT1129-5 VIN = 5.5V, I
6V < V

IN

LT1129 (Note 5) VIN = 4.3V, I

4.8V < V

LT1129-3.3 ΔV

= 4.8V to 20V, I

IN

LT1129-5 ΔVIN = 5.5V to 20V, I

LT1129 (Note 5) ΔVIN = 4.3V to 20V, I

LT1129-3.3 ΔI
ΔI

LT1129-5 ΔI
ΔI

LT1129 (Note 5) ΔI
ΔI

I

= 10mA, TJ = 25°C

LOAD

I

= 10mA

LOAD

I

= 100mA, TJ = 25°C

LOAD

I

= 100mA

LOAD

I

= 500mA, TJ = 25°C

LOAD

I

= 500mA

LOAD

= 700mA, TJ = 25°C

I

LOAD

I

= 700mA

LOAD

I

= 0mA

LOAD

= 10mA

I

LOAD

= 100mA

I

LOAD

= 300mA

I

LOAD

= 500mA

I

LOAD

= 700mA

I

LOAD

= 25°C 150 300 nA

J

= Off to On

OUT

V

= On to Off

OUT

= 0V

SHDN

= 6V, V

V

IN

SHDN

LOAD
LOAD

LOAD
LOAD

LOAD
LOAD

= 0V

= 1mA, TJ = 25°C

OUT

< 20V, 1mA < I

IN

= 1mA, TJ = 25°C

OUT

< 20V, 1mA < I

= 1mA, TJ = 25°C

OUT

< 20V, 1mA < I

IN

OUT

OUT

OUT

OUT

< 700mA

OUT

< 700mA

< 700mA

OUT

= 1mA

= 1mA

= 1mA

= 1mA to 700mA, TJ = 25°C
= 1mA to 700mA

= 1mA to 700mA, TJ = 25°C
= 1mA to 700mA

= 1mA to 700mA, TJ = 25°C
= 1mA to 700mA

3.250

l

3.200

4.925

l

4.850

3.695

l

3.640

l

l

l

l

l

l

3.300

3.300

5.000

5.000

3.750

3.750

3.350

3.400

5.075

5.150

3.805

3.860

1.5 10 mV

1.5 10 mV

1.5 10 mV

6

15

6

20

6

15

20
30

20
30

20
30

mV
mV

mV
mV

mV
mV

0.13 0.20

l

0.25

0.25 0.35

l

0.45

0.37 0.45

l

0.60

0.45 0.55

l

l

l

l

l

l

l

l
l

0.25

l

l

50 70 μA

310 450 μA

2.0 3.5 mA

10 20 mA

25 45 mA

50 90 mA

1.2

0.75

610 μA

15 25 μA

0.70

2.8 V

112935ff

V
V

V
V

V
V

V
V

V
V

V
V

V
V

V

4

LT1129/LT1129-3.3/LT1129-5

OUTPUT CURRENT (A)

DROPOUT VOLTAGE (V)

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0.2

0.4

0.5

112935 G01

0.1

0.3

0.6

0.7

0

= TEST POINTS

TJ ≤ 125°C

TJ ≤ 25°C

TEMPERATURE (°C)

–50

DROPOUT VOLTAGE (V)

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0

50

75

112935 G02

–25

25

100

125

A

C

D

E

B

A. I

LOAD

= 700mA

B. I

LOAD

= 500mA

C. I

LOAD

= 300mA

D. I

LOAD

= 100mA

E. I

LOAD

= 10mA

TEMPERATURE (°C)

–50

QUIESCENT CURRENT (μA)

70

60

50

40

30

20

10

0

0

50

75

112935 G03

–25

25

100

125

V

SHDN

= 0V

V

SHDN

= OPEN (HI)

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating

OUT

= 25°C.

A

RIPPLE

= 0.7A, TJ = 25°C

LOAD

= 0V

= 3.3V, VIN = 0V

OUT

= 5V, VIN = 0V

OUT

= 3.8V, VIN = 0V

OUT

= 0.5V

P-P

,

52 64 dB

l

1.0 mA

16
16
16

voltage will be equal to (V

IN

– V

). Dropout voltage is measured

DROPOUT

between the input pin and the output pin. External voltage drops between
the output pin and the sense pin will add to the dropout voltage.

Note 7: Ground pin current is tested with V

= V

IN

(nominal) and a

OUT

current source load. This means that the device is tested while operating in
its dropout region. This is the worst case ground pin current. The ground
pin current will decrease slightly at higher input voltages.

Note 8: Adjust pin bias current fl ows into the adjust pin.
Note 9: Shutdown pin current at V

= 0V fl ows out of the shutdown pin.

SHDN

Note 10: Quiescent current in shutdown is equal to the sum total of the
shutdown pin current (6μA) and the ground pin current (9μA).

Note 11: Reverse output current is tested with the input pin grounded. The
output pin and the sense pin are forced to the rated output voltage. This
current fl ows into the sense pin and out of the ground pin. For the LT1129
(adjustable version) the sense pin is internally tied to the output pin.

Note 12: The LT1129 regulators are tested and specifi ed under pulse load
conditions such that T
T

= 25°C. For C-grade devices, Regulated Output Voltage, Line Regulation

A

≅ TA. The LT1129C regulators are 100% tested at

J

and Load Regulation performance at –40°C and 125°C is assured by
design, characterization and correlation with statistical process controls.
The LT1129I regulators are guaranteed over the full –40°C to 125°C
operating junction temperature range. The LT1129MP regulators are 100%
tested and guaranteed over the –55°C to 125°C temperature range.

25
25
25

μA
μA
μA

temperature range, otherwise specifi cations are at T

SYMBOL CONDITIONS MIN TYP MAX UNITS

– V

Ripple Rejection V

Current Limit V

Input Reverse Leakage Current V

IN

f

RIPPLE

IN

IN

Reverse Output Current (Note 11) LT1129-3.3 V

LT1129-5 V
LT1129 (Note 5) V

Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.

Note 2: The shutdown pin input voltage rating is required for a low
impedance source. Internal protection devices connected to the shutdown
pin will turn on and clamp the pin to approximately 7V or –0.6V. This
range allows the use of 5V logic devices to drive the pin directly. For high
impedance sources or logic running on supply voltages greater than 5.5V,
the maximum current driven into the shutdown pin must be limited to less
than 20mA.

Note 3: For junction temperatures greater than 110°C, a minimum load
of 1mA is recommended. For T

> 110°C and I

J

may increase by 1%.
Note 4: Operating conditions are limited by maximum junction

temperature. The regulated output voltage specifi cation 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 5: The LT1129 is tested and specifi ed with the adjust pin connected
to the output pin.

Note 6: Dropout voltage is the minimum input/output voltage required to
maintain regulation at the specifi ed output current. In dropout the output

= 1V (Avg), V

OUT

= 120Hz, I

– V

= 7V, TJ = 25°C 1.2 1.6 A

OUT

= –20V, V

< 1mA, output voltage

OUT

TYPICAL PERFORMANCE CHARACTERISTICS

Guaranteed Dropout Voltage Dropout Voltage Quiescent Current

112935ff

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