Introduction

Cost, design time, and unexpected results: These are three of the most significant challenges that weigh on the minds of project managers who are involved with the design of power modules. Whether for use in electric vehicle charging stations, clean energy, variable speed drives, IT equipment power supplies, or any of the hundreds of other applications, modern power modules almost always have one thing in common: Gate drivers are used to control the semiconductor power switches, and optimal power provision can be a challenge. This article reviews current design challenges and discusses innovative solutions to minimize them.

Challenges in Designing Power Supplies 

Gate driver options are extensive, and—with conventional types—the design challenges continue well beyond selection of the driver. Switches need a bias power source to supply the gate power, and this frequently demands the use of multiple power supplies isolated from the controlled ground.

Designing these power supplies occupies significant valuable engineering time. Adding components to the design adds to the cost, size, and complexity of a power module—both in the design and in the bill of materials (BOM)—and the added complexity increases the risk of unexpected results during design validation and in application.

Conventional gate drivers also typically use a bootstrap circuit to create the floating voltage required for controlling the high-side switches. Choosing the optimal combination of components to use in this circuit is, however, often challenging.

An easier design process would be to use a gate driver that also supplies the power needed to control the switches and a single capacitor to create the floating voltage for the high-side switches.

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