LD7792Transition-Mode PFC and Quasi-Resonant Current Mode PWM Controller

The LD7792 is the enhancement version of LD7790, the audible noise produced during start-up & light load is greatly reduced and the THDi is also further improved. LD7792 features transition mode Power Factor Correction (PFC) controller and Quasi-Resonant (QR) current mode controller for cost effective and fewer external components design of high power application.
The intelligent PFC switching on/off, zero current detection (ZCD) and frequency limitation mechanism enable a better efficiency under any load conditions.
The device is also integrated several functions of protection, such as X-CAP discharge, brown-in/out protection, Over Load protection (OLP), Over Temperature Protection (OTP), Over Voltage Protection (OVP) and Over Current Protection (OCP) with high / low line compensation. Therefore it can protect the system from damage due to occasional failure.

The LD7792 is available in a SOP-16 package.




  • Integrated PFC and QR Flyback Controller
  • Transition Mode PFC Controller
  • Quasi-Resonant Operation for Flyback
  • Built-in X-CAP Discharging
  • Brown IN/OUT Protection
  • Internal Soft-Start Function
  • Adjustment OLP Debounce time
  • External Latch Protection
  • PFC Light Load Turn-off Control
  • OVP (Over Voltage Protection)
  • OCP (Cycle by cycle current limiting)
  • 500/-1200mA Driving Capability
  • Internal OTP function



  • AC-DC High Power Adapter
  • Open Frame SMP
  • LED Lighting