ADM1014

–6–

REV.

PrN 1/02

PIN FUNCTION DESCRIPTION (CONTINUED)

Pin

Mnemonic

Function

20

M12VINB

-12V supply input for channel B. Also provides power to the -12V overcurrent circuitry.

21

3VISENB

3.3V current sense for channel B. A current-sensing resistor is connected between this pin and 3VSB

(pin 22). Connect to the load side of the current sense resistor.

22

3VSB

3.3V source for channel B. The source of the 3.3V MOSFET is connected to this pin and a

current-sensing resistor is connected between this pin and pin 21.

23

5VISENB

5V current sense for channel B. A current-sensing resistor is connected between this pin and 5VSB

(pin 24). Connect to the load side of the current sense resistor.

24

5VSB

5V source for channel B. The source of the 5V MOSFET is connected to this pin and a

current-sensing resistor is connected between this pin and pin 23.

25

3V5VGB

3.3V and 5V gate output for channel B, drives the gates of the external 3.3V and 5V MOSFETs.

A capacitor connected from this pin to GND sets the start-up ramp for the 3.3V and 5V supplies.

During turn-on, this capacitor is charged from a 25µA current source. The undervoltage circuitry is

disabled when the voltage on 3V5VGB falls below 12VIN-1.2V.

26

AUXINB

+3.3V auxiliary supply input for channel B.

27

PAUXONB

Power on control for channel B +3.3V auxiliary output. 3.3V CMOS-compatible logic input.

PAUXONB high = outputs on, PAUXONB low = outputs off.

28

12VINB

Switched +12V supply input for channel B.

29

12VINA

Switched +12V supply input for channel A and for OCSET and power-on RESET circuits.

30

PAUXONA

Power on control for channel A +3.3V auxiliary output. 3.3V CMOS-compatible logic input.

PAUXONA high = outputs on, PAUXONA low = outputs off.

31

AUXINA

+3.3V auxiliary supply input for channel A.

32

GND

Ground for all chip circuits. Connect to common of power supplies.

33

3V5VGA

3.3V and 5V gate output for channel A, drives the gates of the external 3.3V and 5V MOSFETs. A

capacitor connected from this pin to GND sets the start-up ramp for the 3.3V and 5V supplies.

During turn-on, this capacitor is charged from a 25µA current source. The undervoltage circuitry is

disabled when the voltage on 3V5VGA falls below 12VIN-1.2V.

34

5VSA

5V source for channel A. The source of the 5V MOSFET is connected to this pin and a

current-sensing resistor is connected between this pin and pin 35.

35

5VISENA

5V current sense for channel A. A current-sensing resistor is connected between this pin and 5VSA

(pin 34). Connect to the load side of the current sense resistor.

36

3VSA

3.3V source for channel A. The source of the 3.3V MOSFET is connected to this pin and a

current-sensing resistor is connected between this pin and pin 37.

37

3VISENA

3.3V current sense for channel A. A current-sensing resistor is connected between this pin and 3VSA

(pin 36). Connect to the load side of the current sense resistor.

38

M12VINA

-12V supply input for channel A. Also provides power to the -12V overcurrent circuitry.