A Novel Single Isolation Channel Gate Driver with Bi-Directional-Signal and Forward-Power Transmission

Conventional isolated gate drivers adopt separate isolation channels for gate driver signal and isolated power supply, which suffers from large signal delays, large size and high cost at medium voltage (MV) and high voltage (HV) applications. Gate drivers with single isolation channel were proposed but suffered from gate driver power instability and limited duty-cycle range. A novel compact single isolation channel with bidirectional-signal and forward-power transmission gate driver is proposed in this paper. Gate driver signal is modulated by pulse edge modulation and transmitted through flyback converter with time-division multiplexing. Feedback signal is modulated by amplitude modulation and demodulated based upon the voltage proportional relationship between primary and secondary side of flyback transformer. 3D vertical packaging is adopted with overall size of 20mm×17mm×16mm. The proposed gate driver achieves max. driving current of 13.8A and can drive silicon carbide devices with max. dv/dt of 154V/ns. It can support max. gate driver signal frequency of 100kHz with duty-cycle ranging from 7.5% to 92.5%. Feedback signal transmission is also demonstrated by DESAT circuit.