A Monolithically Integrated 2-Transistor Voltage Reference With a Wide Temperature Range Based on AlGaN/GaN Technology

Abstract

This letter demonstrates a monolithic voltage reference based on technology of aluminum-gallium- nitride/gallium-nitride (AlGaN/GaN) Metal-Insulator- Semiconductor (MIS) High-Electron-Mobility Transistors (HEMTs). The simple but robust voltage reference consists of only two transistors (2T), namely a depletion-mode (D-mode) device and an enhancement-mode (E-mode) device. This implementation features a 2T structure to generate a predictable reference voltage while maintaining high stability over wide ranges of the supply voltage and temperature. Experimental results show a realization of 2.53 V reference voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}_{REF}$ </tex-math></inline-formula> ) for a supply voltage range of 4.8 to 50 V, a maximum <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}_{REF}$ </tex-math></inline-formula> line sensitivity of 0.077 % <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$/\text{V}$ </tex-math></inline-formula> and a temperature coefficient of 26.2~33.9 ppm/°C in the temperature range from −25 to 250 °C. The voltage reference circuit also features a fast initialization with a start-up time of 387 ns at 25 °C and 841 ns at 250 °C. The results demonstrate a useful design and implementation of a thermally stable reference voltage for applications in biasing and sensing circuits to achieve the compact all-GaN monolithic integration of control/protection blocks in the smart power systems.