April 2009
FAN102
Primary-Side-Control PWM Controller
Features
Constant-Voltage (CV) and Constant-Current (CC)
Control without Secondary-Feedback Circuitry
Green Mode: Frequency Reduction at Light Load
Fixed PWM Frequency at 42kHz with Frequency
Hopping to Reduce EMI
Cable Voltage Drop Compensation in CV Mode
Low Startup Current: 10μA
Low Operating Current: 3.5mA
Peak-Current-Mode Control in CV Mode
Cycle-by-Cycle Current Limiting
VDD Over-Voltage Protection with Auto-Restart
VDD Under-Voltage Lockout (UVLO)
Gate Output Maximum Voltage Clamped at 18V
Fixed Over-Temperature Protection with Auto-
Restart
SOP-8 Package Available
Applications
Battery Chargers for Cellular Phones, Cordless
Phones, PDA, Digital Cameras, Power Tools
Replaces Linear Transformer and RCC SMPS
Offline High Brightness (HB) LED Drivers
Description
The primary-side PWM controller significantly simplifies
power supply design that requires CV and CC regulation
capabilities. The FAN102 controls the output voltage
and current precisely with the information in the primary
side of the power supply, not only removing the output
current sensing loss, but eliminating all secondary
feedback circuitry.
The green-mode function with a low startup current
(10µA) maximizes the light-load efficiency so the power
supply can meet stringent standby power regulations.
Compared with a conventional secondary-side
regulation approach, the FAN102 can reduce total cost,
component count, size, and weight; while
simultaneously increasing efficiency, productivity, and
system reliability.
A typical output CV/CC characteristic envelope is shown
in Figure 1.
Figure 1. Typical Output V-I Characteristic
Ordering Information
Part Number
Operating
Temperature Range
FAN102MY
-40°C to +105°C
Eco Status
Package
Green
8-Lead, Small Outline Package (SOP-8)
Packing
Method
Tape & Reel
For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2008 Fairchild Semiconductor Corporation
FAN102 Rev. 1.0.3
www.fairchildsemi.com