Description

This reference design converts a DC-input source in the range of 450 V to 780 V into non-isolated 390 V at 1.5 A. This is an alternative solution to SiC-FET and SiC-Diode buck converter: since the actual power stage uses only standard silicon components. In order to employ 600 V rated devices: the input source has been split so that two identical buck stages share the center point. A single coupled inductor (1:1) balances automatically the center point. Two small-series inductors limit the current in each branch in case of voltage imbalance and any small variation in the gate drive delay time of the two FETs. The converter minimizes the switching loss as a result of CRM mode (critical conduction mode): achieving peak efficiency of 99% at 450 V input voltage and full load.