CS51220

http://onsemi.com

6

PACKAGE PIN DESCRIPTION

PACKAGE PIN #

PIN SYMBOL

FUNCTION

16 Lead SO Narrow

1

Logic output connecting to external gate driver.

2

GND

Ground.

3

Supply Voltage.

4

3.3 V reference voltage output.

5

Voltage at this pin sets pulse−by−pulse overcurrent thresh-

time, a sink current is generated at this pin. Along with exter-

nal resistors, this current provides a foldback overcurrent

threshold. The sink current is disabled periodically for restart.

6

Current sense input for overcurrent protection.

7

OV

Overvoltage protection monitor.

8

UV

Undervoltage protection monitor.

9

10

SYNCI

By applying sync pulses to this pin, the IC can be synchro-

nized to frequencies ranging from 25% slower to several

times faster than the internal oscillator frequency.

11

DISABLE

Disable mode input pin. A voltage greater than 3.0 V turns off

the whole IC.

12

FF

Feed forward input for PWM ramp. This pin allows external

connection to make the ramp adjustable to the input line.

13

COMP

This pin carries feedback error signal from an external ampli-

fier. Internally, it connects to the PWM controller.

14

SS

A capacitor is connected to this pin for Soft Start and soft

hiccup timing.

15

The voltage at this pin programs the delay of the SYNCO

output in reference to the internal oscillator.

16

SYNCO

Sync output.