LD7792STransition-Mode PFC and Quasi-Resonant Current Mode PWM Controller

The LD7792S is the enhancement version of the LD7790, the audible noise produced during start-up & light load is greatly reduced and the THDi is also further improved. LD7792S 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 LD7792S is available in a SOP-16 package.




  • Integrated PFC and QR or PWM Flyback Controller
  • Transition mode operation for PFC
  • Quasi-resonant operation for Flyback
  • Built-in X-CAP discharging
  • Brown in/out protection
  • Internal soft start function
  • Adjustment OLP debounce time
  • PFC light load turn-off control
  • OVP (Over voltage protection)
  • OCP (Cycle by cycle current limiting)
  • 500/-1000mA driving capability
  • Internal OTP function
  • External OTP protection



  • LED lighting