A novel forward configuration for off-line applications: two-switch built-in input filter forward converter (2SBIFFC)

Employing the transformer leakage inductance, two clamped diodes and two cross-coupled capacitors, a two-switch built-in input filter forward converter (2SBIFFC) configuration is proposed. This configuration is equivalent to the conventional two-switch forward converter (2SFC) with an input filter. It provides a comprehensive solution to perform core reset, turn-off snubber, voltage-clamped and input filter functions with minimum component count. Consequently, low voltage stress, nonpulsating input current, and high efficiency performance can be achieved. In this paper, the circuit operation is analyzed by examining the PSpice simulation waveforms and an experimental circuit of a 100 kHz, 5 V/20 A converter, which was breadboarded for performance evaluation, is described