Offline AC-DC Primary Side PWM Controller for Flyback Converter

  HL9512 Main Photo


The HL9512 is a flyback PWM controller, which operates in a quasi-resonant (QR) and continuous conduction mode (CCM), to significantly enhance system efficiency and power density. The control method is based on load conditions: for heavy load, the valley switching with fixed blanking time is applied; and for medium load, the valley switching with variable blanking time is applied to optimize efficiency. In addition, it offers constant output voltage (CV) regulation through opto-coupler feedback controller with shunt regulator and integrated HV startup. The brown-in voltage is programmed by external DMAG pin resistor.

Wide VDD operating ranges can be allowed for variable output mode applications, such as USB-PD/PPS or conventional DP/DN protocol communication. The HL9512 provides stable gate voltage to drive external power switch thru VREG pin.

The HL9512 has protections, such as VDD over-voltage protection (VDD OVP), VDMAG over-voltage protection (VDMAG OVP), VDMAG under-voltage protection (VDMAG UVP), internal over-temperature protection (OTP), brown-out protection, and externally triggered shut-down (SD) function for safety.


  • High average efficiency by QR and CCM switching operation
  • Wide VDD operating ranges up to 80V
  • Smart driver and frequency hopping for better EMI performance
  • MOSFET Driver compatible
  • mWSaver® Technology for ultra-low standby power consumption (<20mW)
  • Integrated over-voltage protection (OVP), under-voltage protection (UVP), and over-temperature protection (OTP).
  • Programmable thermal shunt down protection through external NTC (SD)
  • Programmable brown-in protection and brown-out protection
  • External depletion MOSFET startup
  • Limit power source (LPS) with adaptive constant current protection (CC)
  • Cycle by cycle current pulse limit (VCS_LIM)
  • Current sense short circuit protection (CSSP)
  • Secondary side diode short protection (SSSP)
  • Accurate protection behavior for auto-restart, latch, and long auto-restart mode

For more information or a full datasheet request, please contact the factory at sales@elevationsemiconductor.com.