4

LTC4350

4350fa

PI FU CTIO S

TYPICAL PERFOR A CE CHARACTERISTICS

FB vs Temperature

Gain Pin Voltage vs Temperature

02

1.210

1.230

4

8

10

4350 G07

1.215

1.225

1.220

6

12

14

TEMPERATURE (°C)

–50

1.210

1.215

1.220

1.225

1.230

–25

025

50

4350 G08

75

100

02

2.2

2.4

2.7

4

8

10

4350 G09

2.3

2.6

2.5

6

12

14

R

TEMPERATURE (°C)

–50

2.2

2.3

2.4

2.5

2.6

2.7

–25

025

50

4350 G10

75

100

R

0

10

11

13

610

4350 G11

9

8

24

812

14

7

6

12

TEMPERATURE (°C)

–50

11.0

11.5

12.0

12.5

13.0

–25

025

50

4350 G12

75

100

UV (Pin 1): Undervoltage Pin. The threshold is set at

1.244V with a 24mV hysteresis. When the UV pin is pulled

high, the charge pump ramps the GATE pin. When the UV

pin is pulled low, the GATE pin will be pulled low.

OV (Pin 2): Overvoltage Pin. The threshold is set at 1.220V

with a 15mV hysteresis. When the OV pin is pulled high,

the GATE pin is pulled low. After a timer cycle, the STATUS

pin is pulled low until the OV pin is pulled low.

TIMER (Pin 3): Analog System Timing Generator Pin. This

pin is used to set the delay before the load sharing turns

on after the UV pin goes high. The other use for the TIMER

pin is to delay the indication of a fault on the STATUS pin.

When the timer is off, an internal N-channel shorts the

TIMER pin to ground. When the timer is turned on, a 2µA

TIMER pin and the voltage starts to ramp up with a slope

trip point (1.220V), the timer will be reset by pulling the

TIMER pin back to ground. The timer period is given by:

GAIN (Pin 4): Analog Output Pin. The voltage across the

a current from the GAIN pin. An external resistor on the

GAIN pin determines the voltage gain from the current

sense resistor to the GAIN pin.