The gFET™ switch: A new low voltage high speed GaAs HEMT for switching applications

The history of power electronics has been characterized by progress mainly based on improved switching devices. SCRs opened the door to modern power electronics. The silicon MOSFET made possible incredible density and efficiency. However, the silicon MOSFET is running out of steam. SiC and GaN are very promising for higher voltages [1] but are poorly suited for low-voltage switches that are so widely used in POL converters. Recently Sarda Technologies has developed a way to make a practical, low cost GaAs high electron mobility transistor (HEMT) for this application. These devices, known as gFET™ switches, offer low on-resistance, essentially negligible capacitance, and sub-nanosecond switching times. This paper describes the construction of these devices, how they operate, and presents the measured electrical characteristics of the prototype devices.