アプリケーションノート 2039

50W Voltage-Mode Forward Converter Design with the MAX8541


要約: This application note details the design of a 50W, isolated forward converter using the MAX8541 synchronizable, high-frequency, voltage-mode PWM controller. Design procedures for both the power stage and controller are presented, along with actual performance measurements.

The converter delivers 20 amps of load current at an output voltage of 2.5V, and employs synchronous rectifiers for secondary rectification. The input voltage range for the converter is 36VDC–75VDC.

This design is available as an evaluation board. The evaluation board demonstrates how easy it is to implement the features network and telecom applications require. The design methods can easily be adapted to the design of high performance, full featured off-line power supplies.

Key features of the application are:
  • 300kHz switching frequency
  • Programmable input UV/OV Protection
  • Programmable hiccup mode and latch type current limit protection
  • Programmable maximum duty cycle clamp with feedforward
  • Adjustable ramp magnitude of MAX8541 voltage mode controller
  • Synchronization to external clock
  • Adjustable current limit threshold
  • Active low-enable feature for easy turn on and turn off
  • Internal leading edge blanking on the current sense pin
  • Output overvoltage protection
  • Space saving 16-pin QSOP