2024年5月3日发(作者：)

LD7575

7/6/2006

Green-Mode PWM Controller with High-Voltage

Start-Up Circuit

REV: 03

General Description

The LD7575 is a current-mode PWM controller with

excellent power-saving operation. It features a high-

voltage current source to directly supply the startup current

from bulk capacitor and further to provide a lossless startup

circuit. The integrated functions such as the leading-edge

blanking of the current sensing, internal slope compensation,

and the small package provide the users a high efficiency,

minimum external component counts, and low cost solution

for AC/DC power applications.

Furthermore, the embedded over voltage protection, over

load protection and the special green-mode control provide

the solution for users to design a high performance power

circuit easily. The LD7575 is offered in both SOP-8 and

DIP-8 package.

g Patent Pending

Features

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High-Voltage (500V) Startup Circuit

Current Mode Control

Non-Audible-Noise Green Mode Control

UVLO (Under Voltage Lockout)

LEB (Leading-Edge Blanking) on CS Pin

Programmable Switching Frequency

Internal Slope Compensation

OVP (Over Voltage Protection) on Vcc

OLP (Over Load Protection)

500mA Driving Capability

Applications

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Switching AC/DC Adapter and Battery Charger

Open Frame Switching Power Supply

LCD Monitor/TV Power

Typical Application

1

Leadtrend Technology Corporation

LD7575-DS-03 July 2006

LD7575

SOP-8 & DIP-8 (TOP VIEW)

V

C

C

6

Pin Configuration

O

U

T

58

N

C

7

H

V

TOP MARK

YYWWPP

1 234

YY:

WW:

PP:

Year code

Week code

Production code

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T

C

O

M

P

G

N

D

C

S

Ordering Information

Part number

LD7575 CS

LD7575 PS

LD7575 CN

LD7575 PN

Package

SOP-8

SOP-8 (PB Free)

DIP-8

DIP-8 (PB Free)

Top Mark

LD7575CS

LD7575PS

LD7575CN

LD7575PN

Shipping

2500 /tape & reel

2500 /tape & reel

3600 /tube /Carton

3600 /tube /Carton

Pin Descriptions

PIN

NAME FUNCTION

This pin is to program the switching frequency. By connecting a resistor to ground

1 RT

to set the switching frequency.

Voltage feedback pin (same as the COMP pin in UC384X), By connecting a

2 COMP

photo-coupler to close the control loop and achieve the regulation.

3

5

CS

OUT

Current sense pin, connect to sense the MOSFET current

Gate drive output to drive the external MOSFET

4 GND Ground

6 VCC Supply voltage pin

7 NC Unconnected Pin

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

8 HV for the controller. When Vcc voltage trips the UVLO(on), this HV loop will be off to

save the power loss on the startup circuit.

2

Leadtrend Technology Corporation

LD7575-DS-03 July 2006