EUP3482

DS3482

Ver1.3

Feb. 2011

2

Typical Application Circuit (continued)

Figure2. 24V to 3.3V/5V Application Circuit

Pin Configurations

Package Type

Pin Configurations

SOP-8

Pin Description

PIN

PIN NAME

DESCRIPTION

1

BS

High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel DMOS

switch. Connect a 0.01µF or greater capacitor from SW to BS to power the high side switch.

2

IN

Input Supply Pin. IN supplies the power to the IC, as well as the step-down converter switches.

Drive IN with a 4.5V to 30V power source. Bypass IN to GND with a suitably large capacitor

to minimize input ripple to the IC. See Input Capacitor Section of the applications notes.

3

SW

Power Switching Output. Connect the output LC filter from SW to the output load.

4

GND

Ground.

5

FB

Output Feedback Input. FB senses the output voltage and regulates it. Drive FB with a resistive

voltage divider connected to it from the output voltage. The feedback threshold is 0.923V.

See Setting the Output Voltage.

6

COMP

Loop compensation Input. Connect a series RC network from COMP to GND to compensate

the regulation control loop. See Compensation.

7

EN

Enable Input. EN is a logic input that controls the regulator on or off. Drive EN high to turn on

the regulator; low to turn it off. Don’t leave EN pin floating. Directly connect EN to IN (or

through a resistance) for automatic startup.

8

SS

Soft-Start Control Input. Connect an external capacitor to program the soft-start. If unused,

leave it open, which means internal soft-start function.