Green mode Quasi-resonant ICs


  • Status:Available

FA5641 is a quasi-resonant switching power supply control IC with excellent low standby power. Despite its compact 8-pin package, it has a wide variety of functions and reduces the number of external components, thereby enabling the configuration of space-saving and cost-effective power supplies.


  • Quasi-resonant switching power supply
  • Power supply with excellent standby characteristicsIncorporates a startup circuit to achieve low power consumption
  • Low current consumption of 0.85 mA during operation
  • Bottom skip count control with on-off width detection
  • Light-load burst operation function
  • Built-in drive circuit that can directly connect power MOSFETs
    1. Output current: 0.5 A (sink) / 0.25 A (source)
  • Built-in overload protection (spring return)
  • Built-in latch protection with secondary overvoltage detection
  • Built-in input voltage correction
    1. Switches between the IS pin’s maximum input threshold voltage and pulse stop FB voltage
  • Built-in low-voltage malfunction prevention circuit (14 V ON/8 V OFF)
  • Minimum oscillation frequency limiting function: 25 kHz
  • Package: SOP-8


  • Switching Power Supplies


Controller type QR
Applied circuit Detail Flyback
Frequency (kHz) Selfoscillation (With control of bottom skips)
VCC(V) 11 to 26
Built-in start up circuit (V) 500
Over load protection Auto-Recovery
Over voltage protection Latch (ZCD)
Package SOP-8

Documentation Tools

Reference Design Power Supply Control IC Reference Design
Selection Guide Power Supply Control IC Selection Guide



Block diagram

Circuit diagram

Outline drawing

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