
2006 Fairchild Semiconductor Corporation
FS6X0420RJ/ FS6X0720RJ/ FS6X1220RJ Rev. 1.0.1
1
www.fairchildsemi.com
March 2006
F
FPS
TM
is a trademark of Fairchild Semiconductor Corporation
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
OUTPUT POWER TABLE
(1)
PRODUCT
36V
DC
~72V
DC
14W
FS6X0420RJ
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
FS6X1220RJX
(2)
-25
°
C to +85
°
C
Yes
D2-Pak-6L
Tape & Reel
6X0720R
-25
°
C to +85
°
C
Yes
D2-Pak-6L
Tape & Reel
6X1220R