SC4525A

5

Pin Descriptions

SO-8

Pin Name

Pin Function



SW

Emitter of the internal NPN power transistor. Connect this pin to the inductor, the freewheeling diode and the

bootstrap capacitor.

2

IN

Power supply to the regulator. It is also the collector of the internal NPN power transistor. It must be closely by-

passed to the ground plane.

3

ROSC

An external resistor from this pin to ground sets the oscillator frequency.

4

GND

Ground pin

5

SS/EN

Soft-start and regulator enable pin. A capacitor from this pin to ground provides soft-start and overload hiccup

functions. Hiccup can be disabled by overcoming the internal soft-start discharging current with an external pull-

up resistor connected between the SS/EN and the IN pins. Pulling the SS/EN pin below 0.2V completely shuts off

the regulator to low current state.

6

COMP

The output of the internal error amplifier. The voltage at this pin controls the peak switch current. A RC compensa-

tion network at this pin stabilizes the regulator.

7

FB

The inverting input of the error amplifier. If V

improve short-circuit robustness (see Applications Information for details).

8

BST

Supply pin to the power transistor driver. Tie to an external diode-capacitor bootstrap circuit to generate drive

voltage higher than V

9

Exposed Pad

The exposed pad serves as a thermal contact to the circuit board. It is to be soldered to the ground plane of the

PC board.