LT4256-3

3

42563f

FB Voltage Threshold

FB High-to-Low Transition

q

3.95

3.99

4.03

V

FB Low-to-High Transition

q

4.20

4.45

4.65

V

FB Hysteresis Voltage

0.3

0.45

0.60

V

PWRGD Output Low Voltage

0.25

0.4

V

0.60

1.0

V

PWRGD Pin Leakage Current

0.1

1

µA

FB Input Current

FB = 4.5V

–0.1

–1

µA

TIMER Pull-Up Current

q

– 85

– 115

–145

µA

TIMER Pull-Down Current

q

1.5

3

5

µA

TIMER Shutdown Threshold

q

4.3

4.65

5

V

Duty Cycle (RETRY Mode)

q

1.5

3

4.5

%

RETRY Threshold

q

0.4

0.85

1.2

V

RETRY Input Current

RETRY = GND

–87

–130

µA

UV Low to GATE Low

1.7

3

µs

UV High to GATE High

6

9

µs

FB Low to PWRGD Low

0.8

2

µs

FB High to PWRGD High

3.2

5

µs

1

3

µs

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Note 1: Absolute Maximum Ratings are those values beyond which the life

of a device may be impaired.

Note 2: An internal clamp limits the GATE pin to a minimum of 10V above

the part.

TYPICAL PERFOR A CE CHARACTERISTICS

SENSE Regulation Voltage

vs Temperature

TEMPERATURE (

°C)

–50

10

15

20

48

58

–25

025

50

42563 G01

75

100

53

FB = 0V

FB > 2V

10

2.0

2.5

3.5

40

60

42563 G02

1.5

1.0

20

30

50

70

80

0.5

0

3.0

TEMPERATURE (

°C)

–50

0

0.5

1.0

1.5

2.5

–25

025

50

42563 G03

75

100

2.0