A 0.7-V 7.4-nW 6.4-ppm/°C CMOS Subthreshold Voltage Reference With Temperature Compensation Circuit

Abstract

This paper proposes a nanowatt voltage reference (VR) with temperature coefficient compensation. All transistors work in the subthreshold region. 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 proposed VR circuit can generate a reference voltage with a wider temperature range and a lower temperature coefficient. The proposed VR circuit is implemented using a standard 0.18-μm CMOS process with an active area of only 0.022 mm2. The postlayout simulation results show that the proposed VR circuit generates a reference voltage of 308.21 mV at room temperature. Its temperature coefficient is 6.4 ppm/°C over a temperature range of −40°C°C–140°C, with a power consumption of 7.4 nW. The voltage line sensitivity (LS) is 0.098%/V, and the power supply ripple rejection (PSRR) is −72 dB @DC and −42 dB @10 MHz.

Jingjing Liu

Associate Professor

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

Yuxuan Huang

M.Sc.

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

Yuchen Wang

Master’s Student

My research interests include the design of high dynamic range and multi-mode image sensors.

Jian Guan

PhD Student

My research interests include the design of solar cells and energy harvesting circuits.

Zhipeng Li

PhD Student

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