A Supply Voltage Insensitive Two-Transistor Temperature Sensor with PTAT/CTAT Outputs based on Monolithic GaN Integrated Circuits

The article presents a monolithically integrated temperature sensor using a two-transistor (2 T) configuration based on gallium nitride (GaN) metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs). By adjusting the gate size ratio of the depletion-mode (D-mode) device and enhancement-mode (E-mode) device, the output type of the sensor can be converted from proportional to absolute temperature (PTAT) and complementary to absolute temperature (CTAT). Experimental results demonstrate that the 2 T configuration achieves PTAT/CTAT output with high temperature sensitivity (PTAT/CTAT: 15.86/$-$10.53 mV/$^\circ$C) over a wide temperature range of 25 °C-250 °C and a broad supply voltage range of 8-60 V, attributed to the superior characteristics of the GaN transistor. In addition, the integrated over-temperature protection (OTP) block based on this temperature sensor has been fabricated in the laboratory, which features a fast response time (381 ns at 150 $^\circ$C). These results demonstrate the viability of on-chip integrated sensors in OTP circuits that are fully compatible with 48 V applications and a high-temperature environment, paving the way for the development of high-power density all-GaN smart power systems.