IC manufacturers Onsemi

IC manufacturers (96)

Onsemi FAN103

Primary-Side-Regulation PWM Controller


TopologyFlyback Converter
Switching frequency47-53 kHz
IC revision1.0.7


This third-generation Primary Side Regulation (PSR) and highly integrated PWM controller provides several features to enhance the performance of low-power flyback converters. The proprietary topology, TRUECURRENT®, of FAN103 enables precise CC regulation and simplified circuit for battery charger applications. A low-cost, smaller and lighter charger results as compared to a conventional design or a linear transformer.

To minimize standby power consumption, the proprietary green-mode function provides off-time modulation to linearly decrease PWM frequency under light-load conditions. This green mode assists the power supply in meeting the power conservation requirement.

By using the FAN103, a charger can be implemented with few external components and minimized cost.


  • Low Standby Power Under 30mW
  • High-Voltage Startup
  • Fewest External Component Counts
  • Constant-Voltage (CV) and Constant-Current (CC) Control without Secondary-Feedback Circuitry
  • Green-Mode Function: Linearly-Decreasing PWM Frequency
  • Fixed PWM Frequency at 50kHz with Frequency Hopping to Solve EMI Problem
  • Cable Compensation in CV Mode
  • Peak-Current-Mode Control in CV Mode
  • Cycle-by-Cycle Current Limiting
  • VDD Over-Voltage Protection with Auto Restart
  • VDDUnder-Voltage Lockout (UVLO)
  • Gate Output Maximum Voltage Clamped at 15V
  • Fixed Over-Temperature Protection with Auto Restart
  • Available in the 8-Lead SOP Package

Remarks:Inductors 1mH , 4.7uH And Transformer Used

Typical applications

  • Battery chargers for cellular phone,cordlessphone, PDA, digital camera ,power tools,etc
  • Replaces linear transformer and RCC SMPS


Order Code Data­sheet Downloads Product series Samples
Flyback Transformer
Order Code Data­sheet
Order Code Data­sheet Downloads Product series Samples