Enhancement-mode p-GaN Comparators for power applications.

This paper presents the design of three new comparators circuits for power applications using Enhancement-mode p-GaN HEMT Process Design Kit (PDK) developed by IMEC. The design challenge in this technology is the lack of P-type devices, therefore diode-connected structures with N-type devices are introduced as pull-up devices. Comparators are monolithicaly integrated with 200V/10A power p-GaN HEMTs. The output voltage of the comparators is set to 6V to turn-on the power device suitably. To verify the performance of the circuits, 1MHz of input signal frequency is selected. Relevant parameters such as rising, falling and propagation delay times, together with the power-delay product are discussed. For rated output voltage and frequency, the lower rise/fall/propagation delay times achieved are 0.83/0.89/1.14 ns. Transistor-level simulations and proof of concept of each proposed structure are carried out considering temperature and frequency variation.