IR3629/IR3629A MPbF

11/26/2007

Pin Description

Pin Name

Description

1

PGood

Power Good status pin. Output is open collector. Connect a pull up

resistor from this pin to Vcc.

2

Vcc

This pin provides biasing voltage for the internal blocks of the IC. It also

biases the low side driver. A minimum of 0.1uF, high frequency capacitor

must be connected from this pin to power ground.

3

LDrv

Output driver for the low side MOSFET

4

PGnd

Power Ground. This pin serves as a separate ground for the MOSFET

drivers and should be connected to the system’s power ground plane.

5

HDrv

Output driver for the high side MOSFET

6

Vc

This pin powers the high side driver and must be connected to a voltage

higher than bus voltage. A minimum of 0.1uF, high frequency capacitor

must be connected from this pin to power ground.

7

Vsns

PGood sense pin

8

Fb

Inverting input to the error amplifier. This pin is connected directly to the

output of the regulator via resistor divider to set the output voltage and

provide feedback to the error amplifier.

9

Comp

Output of the error amplifier.

10

Gnd

Signal ground for internal reference and control circuitry.

11

SS/SD

Soft start / shutdown. This pin provides user programmable soft-start

function. Connect an external capacitor from this pin to ground to set the

start up time of the output voltage. The converter can be shutdown by

pulling this pin below 0.3V.

12

OCSet

Current limit set point. A resistor from this pin to drain of the low side

MOSFET will set the current limit threshold.

4