Faster-Switching GaN Presenting a number of interesting measurement challenges by Steve Sandler T he advancement of gallium nitride (GaN) power switches brings with it a multitude of performance benefits while also providing many challenges. While GaN switches may be very close to the mainstream, our ability to perform the high-fidelity measurements necessary for characterizing, troubleshooting, and optimizing their implementation is considerably lagging. This article illustrates some of these significant challenges using real-world measurements for both switching and linear power applications. Some proven and some potentially viable solutions and techniques are presented. One of the most obvious benefits of GaN-based devices compared with silicon (Si) is much faster switching. The average Si MOSFET switch has an edge speed in the range of 1-5 ns for a typical low-voltage integrated switching regulator and 10-30 ns for an external MOSFET regulator. By comparison, the state-ofthe-art low-voltage GaN switch can be two orders of magnitude faster. This speed is achieved in large part due to a smaller device with a much lower capacitance. Enhancement-mode (eGaN) devices also result in a significant advantage in the chipscale packaging and the consequent reduction in inductance, while new GaN packages also strive for lower inductance. In addition to being smaller and faster, GaN switches also offer lower on-state resistance and a lower production cost compared with Si MOSFETs. The focus of this article is to look at the significant measurement challenges that these new performance features bring with them. These include the traditional power switch measurements, such as switching and conduction losses, as well as newer requirements for investigating the electromagnetic interference (EMI) resulting from the switching operation. Digital Object Identifier 10.1109/MPEL.2015.2420232 Date of publication: 24 June 2015 24 IEEE POWER ELECTRONICS MAGAZINE June 2015 2329-9207/15©2015IEEE