©2006 Fairchild Semiconductor Corporation

1

www.fairchildsemi.com

March 2006

FS6X0420RJ/ FS6X0720RJ/ FS6X1220RJ Rev. 1.0.1

FS6X0420RJ/ FS6X0720RJ/ FS6X1220RJ

Fairchild Power Switch (FPS™)

Features

Current Mode PWM Control with a Fixed Operating Fre-

quency (300kHz)

Pulse by Pulse Current Limit

Over Load Protection

Over Voltage Protection

Thermal Shutdown

Line Under Voltage Detection and Sleep on/off Function

Internal High Voltage SenseFET (200V)

Supports Forward or Flyback Topology

Applications

DC-DC Converter

PoE Device

Related Application Notes

AN4137 - Design Guidelines for Off-line Flyback Converters

Using Fairchild Power Switch (FPS)

AN4140 - Transformer Design Consideration for Off-line Fly-

back Converters using Fairchild Power Switch

AN4141 - Troubleshooting and Design Tips for Fairchild

Power Switch Flyback Applications

AN4148 - Audible Noise Reduction Techniques for FPS

Applications

Description

The FS6X-Series is specially designed for off-line DC-DC con-

verters with minimal external components. This device com-

bines a current mode PWM controller with a high voltage power

SenseFET in a single package. The PWM controller includes

integrated fixed frequency oscillator, line under voltage lockout,

sleep on/off function, thermal shutdown protection, over voltage

protection, pulse-by-pulse current limit, and temperature com-

pensated precise current sources for a loop compensation.

Compared with the discrete MOSFET and PWM controller solu-

tion, the FS6X-Series can reduce total cost, component count,

size, and weight, while simultaneously increasing efficiency,

productivity, and system reliability.

Table 1. Maximum Output Power

Note:

1. Maximum practical continuous power in an open

frame design at 50

°C ambient.

Ordering Information

Note:

2. X : Tape & Reel

PRODUCT

FS6X0420RJ

14W

FS6X0720RJ

26W

FS6X1220RJ

36W

Part Number

Operating Temp.

Range

Pb-Free

Package

Packing Method

Marking

Code

FS6X0420RJ

-25

°C to +85°C

Yes

D2-Pak-6L

Tube

6X0420R

FS6X0720RJ

-25

°C to +85°C

Yes

D2-Pak-6L

Tube

6X0720R

FS6X1220RJ

-25

°C to +85°C

Yes

D2-Pak-6L

Tube

6X1220R

FS6X0420RJX

-25

°C to +85°C

Yes

D2-Pak-6L

Tape & Reel

6X0420R

FS6X0720RJX

-25

°C to +85°C

Yes

D2-Pak-6L

Tape & Reel

6X0720R

-25

°C to +85°C

Yes

D2-Pak-6L

Tape & Reel

6X1220R