A Three-Channel Package-Scale Galvanic Isolation Interface for Wide Bandgap Gate Drivers

Abstract

This article presents the design of a three-channel package-scale galvanic isolation interface for SiC and GaN power switching converters. The isolation interface consists of two side-by-side co-packaged chips fabricated in a low-cost 0.32-µm bipolar CMOS-DMOS (BCD) technology and includes three isolation data channels based on RF-coupled integrated microantennas. The isolation interface provides a channel for the gate driver control, a bidirectional channel for diagnostic, and a channel for the isolated power supply control. They use on-off keying (OOK)-modulated RF carriers of 1.5, 0.5, and 1.5 GHz, respectively. The galvanic isolation interface provides a maximum signal rate of 2 and 1.9 MHz for the driver and the power control channels, respectively, whereas the diagnostic channel guarantees half-duplex bidirectional communication up to 15 MHz. Thanks to the package-scale isolation approach, both reinforced galvanic isolation and first-rate common-mode transient immunity (CMTI) are achieved. High immunity to adjacent channel crosstalk is guaranteed by using channel frequency/physical separation. To best of the authors' knowledge, this is the first implementation of a package-scale galvanic isolation interface with three independent communication channels, including a bidirectional channel, in silicon technology.