A High Temperature 4H-SiC Voltage Reference for Depletion Mode GaN-Based Circuits
Abstract High temperature electronics are highly demanded for many applications such as automotive, space, and oil and gas exploration. Electronic circuits for those applications are required to operate reliably without using bulky cooling systems. Circuits based on silicon (Si) suffer from high leakage currents at high temperatures. Silicon Carbide (SiC) circuits, on the other hand, are suitable for high temperature applications due to the wide bandgap and offer high breakdown voltage and low leakage current. This paper presents a negative voltage reference for high temperature applications using commercial-off-the-shelf (COTS) 4H-SiC transistors. The proposed voltage reference adopts Widlar bandgap reference topology, and it aims to provide a negative reference voltage for Gallium Nitride (GaN) circuits operating at high temperatures. Measurement results indicate that the proposed circuit provides a negative reference voltage with a low temperature coefficient of 42 ppm/°C for temperatures ranging from 25 °C to 250 °C. The proposed circuit also operates reliably for a wide supply voltage range of −7.5 V to −15 V for the temperature range.