Description

This reference design provides isolated positive and negative voltage rails required for Insulated Gate Bipolar Transistor (IGBT) gate drivers from a single 24-volt DC input supply. Utilizing a Fly-Buck™ control topology: this reference design uses a single transformer for generating power rails for all three arms of the 3-phase inverter.  It uses primary-side regulation and can achieve good cross regulation without opto-coupler feedback or an auxiliary winding. The isolated outputs are generated through the coupled windings of the transformer. The voltage rails for all the high-side IGBTs are individually isolated: whereas the voltage rails for all low-side IGBTs are combined.