GaN Single-Polarity Power Supply Bootstrapped Comparator for High-Temperature Electronics

A high-performance bootstrapped comparator operating with a single-polarity power supply is demonstrated for GaN high-temperature electronics applications. The comparator features monolithically integrated enhancement-mode (E-mode) and depletion-mode (D-mode) AlGaN/GaN HEMTs. The tail current source uses an E-mode HEMT, enabling single-polarity power supply. The E-mode input stage could cover a wide voltage comparison range (from 1 to 6 V) while the bootstrapped loads are implemented with D-mode HEMTs. At room temperature, the comparator delivers a voltage gain as high as 79 V/V and a unity-gain bandwidth of 206 MHz. At 250 , a maximum voltage gain of 40 V/V and a unity-gain bandwidth of 84 MHz are obtained.