An Optically Isolated Gate Driver with Simultaneous Data and Power Transmission through a Miniaturized, Efficient Photonic Platform

This paper presents the design and implementation of an efficient optically-isolated gate driver that can be used for wide bandgap (WBG) devices in a wide range of high-voltage power conversion circuits where galvanically-isolated gate driving is a key challenge. The proposed isolated gate driving system achieves simultaneous signal and power transmission through a modulated LED transmitter and galvanically-isolated silicon photovoltaic receiver. Peak transmission efficiency (LED + PV combined) of the optical system was 15.1% for a single cells and 11.2% for a module comprising two series cells while achieving over 5 kV isolation and < 2.5 pF capacitance across the isolation barrier. A forward-mode receiver circuit was designed to recover a switching signal from modulated LED current. A switched-capacitor-based gate drive circuit was used to multiply the PV cell voltage in sequential steps while recovering gate charge energy to provide up to 30% total efficiency for the combined system.