LD9535TMulti-Mode PWM Controller of Flyback with MOSFET Integrated

The LD9535T is built in a multi-mode PWM controller and integrated a 650V MOSFET. The multi-mode PWM controller which consists of Quasi-Resonant (QR) PWM control for light load condition and Continue Conduction Mode (CCM) for heavy load condition. Moreover, the QR controller not only gains the system performance, but also brings the worse EMI capability, while the frequency swapping function of LD9535T can reduce the EMI emission of SMPS and helps the power circuit designers to simply deal with EMI filter and saves several component and developing time.
The LD9535T is implemented in DIP-8 package, and includes the comprehensive protection function, such as Over Load Protection (OLP), Over Voltage Protection (OVP), Output Short Circuit Protection (OSCP) and internal Over Temperature Protection (OTP).



  • Secondary-side feedback control with quasi-resonant + CCM operation
  • Built-in 650V MOSFET Switch
  • Low Startup Current (<1mA)
  • Ultra-low operating current at light load
  • Cycle-by-Cycle Current Limit
  • Green Mode Control
  • UVLO (Under Voltage Lockout)
  • LEB (Leading-Edge Blanking) on CS Pin
  • VCC OVP (Over Voltage Protection)
  • Adj. OVP (Over Voltage Protection) on FB pin.
  • Adj. UVP (Under Voltage Protection) on FB pin.
  • OLP (Over Load Protection)
  • Internal OTP (Over Temperature Protection)


  • Switching AC/DC Adaptor
  • Open Frame Switching Power Supply