We recently did a short video with Alex Lidow from EPC who took us through a demonstration of a gate driver integrated onto the same chip as eGaN transistor. Driving the gate of the power transistor is complicated because of the parasitic elements.
Lidow explained that eGaN transistors switch in a nanosecond or less, and designers have had to buy an external gate drive made in silicon to drive them. Often parasitic inductances will either slow down the device or create noisy ringing, and it becomes a difficult thing for the designer. That’s the reason for integrating the drive electronics onto the GaN transistor chip. The demo involves the EPC2112, a 200-V device with an integrated driver. The GaN device is powered from a CMOS logic chip. It doesn’t take any driver, just a very low-current logic signal.
The demo drives the chip with about a five nanosecond rise time, and Lidow says the devices can operate in the six and seven megahertz range for wireless power applications.
A second EPC chip carries two drivers and two transistors. Lidow says it is really meant for differential mode class A amplifiers as might be found in a wireless power system. In the demo, a small 1.5×2.5-mm chip powers a Class 3 wireless power transmitter.