3

LT1129/LT1129-3.3/LT1129-5

ELECTRICAL C

C

HARA TERISTICS

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Dropout Voltage

0.13

0.20

V

(Note 5)

q

0.25

V

0.25

0.35

V

q

0.45

V

0.37

0.45

V

q

0.60

V

0.45

0.55

V

q

0.70

V

Ground Pin Current

q

50

70

µA

(Note 6)

q

310

450

µA

q

2.0

3.5

mA

q

10

20

mA

q

25

45

mA

q

50

90

mA

Adjust Pin Bias Current (Notes 4, 7)

150

300

nA

Shutdown Threshold

q

1.2

2.8

V

q

0.25

0.75

V

Shutdown Pin Current (Note 8)

q

610

µA

Quiescent Current in Shutdown

q

15

25

µA

(Note 9)

Ripple Rejection

64

dB

Current Limit

1.2

1.6

A

Input Reverse Leakage Current

q

1.0

mA

Reverse Output Current (Note 10)

LT1129-3.3

16

25

µA

LT1129-5

16

25

µA

LT1129 (Note 4)

16

25

µA

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.

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 7: Adjust pin bias current flows into the adjust pin.

Note 9: Quiescent current in shutdown is equal to the sum total of the

shutdown pin current (6

µA) and the ground pin current (9µA).

Note 10: 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 flows 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 11: For C grade devices Regulated Output Voltage, Line Regulation,

and Load Regulation are guaranteed over the extended temperature range

of – 40

°C to 125°C. These parameters are not tested or quality assurance

sampled at –40

°C. They are guaranteed by design, correlation and/or

inference from 25

°C and/or 0°C tests.

range.

Note 1: 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 2: For junction temperatures greater than 110

°C, a minimum load of

may increase by 1%.

Note 3: 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 4: The LT1129 is tested and specified with the adjust pin connected

to the output pin.

Note 5: Dropout voltage is the minimum input/output voltage required to

maintain regulation at the specified output current. In dropout the output