Hybrid switch control

Abstract

A hybrid switch apparatus includes a standard semiconductor switch and a fast semiconductor switch electrically arranged in parallel to form a joint output current path for carrying a load current. The standard switch may be a silicon (Si) MOSFET while the fast switch may be a GaN high electron mobility transistor (HEMT). A means for producing first and second gate drive signals includes a pulse former. The first gate drive signal is applied the standard switch for selectively turning the standard switch on and off. The pulse former outputs the second gate drive signal for driving the fast switch, where the pulse former generates the second gate drive signal as a switch-on pulse starting synchronously with each transition of the first gate drive signal and which generates the second gate drive signal in an OFF state in between pulses to avoid incurring a conduction loss in the fast switch.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS [0002] This application claims the benefit of US Provisional Application No. 62 / 466,326, filed March 2, 2017 (the '326 application), which is incorporated herein by reference as if fully set forth herein. Background technique [0003] a.Technical field [0004] The present disclosure relates generally to power electronics systems, and more particularly to an apparatus for controlling a hybrid switch comprising: a first (fast) semiconductor switching device, such as a fast GaN high electron mobility transistor (HEMT ); and a second (slower) semiconductor switching device, such as a silicon (Si) metal oxide semiconductor field effect transistor (MOSFET). [0005] b. Background technology [0006] This background description is set forth below for the purpose of providing background only. Therefore, any aspect of this background description, in the sense that it is otherwise prior art, is neither explicitly nor implicitly admitt...

AI Technical Summary

Problems solved by technology

However, WBG devices still have their own challenges

[0009] First, the current capability is still not high enough for some applications compared to silicon devices

For this high current application, multiple WBG switches need to be connected in parallel, which increases the system cost

Second, especially for so-called GaN High Electron Mobility Transistor (HEMT) devices, WBG devices have much higher reverse conduction losses than e.g. silicon MOSFET devices when the switch is not "on"

This reverse conduction loss characteristic limits system efficiency

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