Introduction

The Offline PFC Flyback 12V/8A Evaluation Board is an isolated AC/DC power supply designed to generate a regulated 12V DC output from an AC mains input. The board was measured over an input voltage range of 180 VAC to 265 VAC. Nominal performance characterization was performed at 230 VAC.

The board uses a flyback topology and secondary-side firmware control to regulate the output voltage. The control system monitors output feedback signals, computes the required control response, and generates a switching command for the primary-side power stage. The firmware also manages operating-range selection and overvoltage protection.

The board consists of the following major functional blocks:

  • AC input protection and EMI filtering
  • Bridge rectifier and high-voltage DC bus
  • Flyback transformer and primary-side switching stage
  • MCP1012 primary-side start-up and gate-drive circuit
  • Isolated pulse feedback interface
  • PIC16F18326 secondary-side controller
  • Secondary side synchronous rectification and output filter
  • Output voltage feedback network
  • Auxiliary low-voltage supply

The board is intended for evaluation over the measured 180 VAC to 265 VAC input range and provides a regulated output of approximately 12V DC up to 8A.