The Influence of Gate-Series-Resistor on the ESD Protection and Switching Speed for 650V GaNHEMT Circuit

Unlike CMOS technology, there only exist two components, HEMT and resistor, that can be used to design as the electrostatic-discharge (ESD) protection circuit in GaN technology. Although HEMT has very robust ESD capability, it still cannot work very well without the resistor to clamp the ESD current or pull up the gate voltage to turn on its channel. So, most ESD protection circuits for protected HEMT are composed of resistor and HEMT. In general, the protection capability of an ESD protection circuit is determined by the size of ESD HEMT and the resistor resistance. However, the high-resistance resistor degrades the switching speed of protected HEMT, while the low-resistance resistor degrades the protection capability of ESD protection circuit. In this paper, how the turn-on gate resistor (RgON) affects the protection capability of all-terminal ESD protection circuit for a 650V GaN HEM is studied. From the test results, this protection circuit is demonstrated that can protect the gate of protected HEMT against 1 kV HBM strike for any zapping condition even if the RgON is only 2ohm.