LD7576/76H/76J/76K

3

Leadtrend Technology Corporation

www.leadtrend.com.tw

LD7576-DS-04a

December 2009

2.

LD7576H/76K features Built-in latch-mode function of OVP on Vcc pin , OLP and On Chip OTP.

3.

LD7576/76J features Built-in Auto-Recovery function of OVP on Vcc pin OLP and On Chip OTP.

Pin Descriptions

PIN

NAME

FUNCTION

1

CT

This pin is to program the frequency of a lower frequency timer.

Connecting a

capacitor to ground sets the OLP delay time.

This pin can be used for latch mode protection as well. By pulling this pin lower than

0.8 V, the controller will be entered latch mode until the AC power-on recycling.

2

COMP

Voltage feedback pin (same as the COMP pin in UC384X). Connecting a

photo-coupler closes the control loop to achieve the regulation. A high quality

ceramic capacitor (X7R), with capacitance of 102pF at least, is required for general

applications.

3

CS

Current sense pin, for sensing the MOSFET current.

4

GND

Ground.

5

OUT

Gate drive output to drive an external MOSFET.

6

VCC

Supply voltage pin.

7

NC

Unconnected Pin.

8

HV

Connect this pin to a positive terminal of a bulk capacitor to provide the startup

current for the controller. When Vcc voltage trips up to the UVLO(on), this HV loop

will be off to save the power loss on the startup circuit.