An Ultra-low Power CMOS Subthreshold Voltage Reference with Temperature Coefficient Compensation

Abstract

This paper presents a nanowatt voltage reference (VR) with an ultra-low power consumption temperature coefficient compensation. All transistors are biased in the subthreshold region to reduce the power consumption of the proposed VR circuit. The complementary-to-absolute-temperature (CTAT) voltage and proportional-to-absolute-temperature (PTAT) voltage are mainly generated by two NMOS transistors with different threshold voltages. At the same time, a simple temperature compensation circuit is designed to optimize the temperature coefficient at high temperatures, so that the circuit can generate a reference voltage with a wider temperature range and a lower temperature coefficient. The proposed VR circuit is fabricated in a 0.18-μm CMOS process with a silicon area of only 0.022 mm2. Theoretical analysis and post-layout simulation results verified the reliability and performance improvement of circuit operation. The proposed VR circuit generates a reference voltage of 308.21 mV with a temperature coefficient of 6.42 ppm/℃ over a wide temperature range of −40 ~ 40 ℃. The power consumption of the circuit is 7.04 nW. The voltage line sensitivity (LS) is 0.099%/V.

Yuxuan Huang

M.Sc.

My research interests include circuit design of low-power reference.

Ruihuang Wu

M.Sc.

My research interests include circuit design of delay loop lock.

Bingjun Xiong

PhD

My research interests include circuit design of optical receivers and references.

Zhipeng Li

PhD Student

My research interests include circuit design of image sensors and energy harvesting circuits.

Yun Zou

Master’s Student

My research interests include the design of hyper materials and antennas.

Jingjing Liu

Associate Professor

My research interests include low-power smart micro-sensor integrated circuit design, image sensors, biomedical sensors, and energy harvesting circuits.