A 3.7-nW 248-ppm/°C Subthreshold Self-Biased CMOS Current Reference

Abstract

A modified self-biased β -multiplier-based current reference (CR) circuit is proposed for ultralow-power Internet of Things (IoT) application and is realized without any resistors, bipolar junction transistors (BJTs), or operational amplifiers (OPAs). The proposed CR circuit directly generates the reference current from a modified β -multiplier, which is biased by a stacked diode-connected MOS transistor (SDMT)-based compensated through a complementary-to-absolute temperature (CTAT) voltage. The proposed CR is implemented in a standard 0.18- μ m CMOS process with an active area of 0.0069 mm2 and almost all transistors operate in the subthreshold region. Measurement results show that the temperature coefficient (TC) of the CR is 248 ppm/°C in a temperature range from −40 ∘ C to 125 ∘ C. The proposed CR exhibits a line sensitivity (LS) of 0.33%/V within the supply voltage range of 0.8–1.4 V. The output of the CR at room temperature ( 25 ∘ C) is 1.84 nA with a power consumption of 3.7 nW.

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.

Weijie Ge

PhD Student

My research interests include the design of radio frequency integrated circuits and energy harvesting circuits.

Wenji Mo

Master’s Student

My research interests include circuit design of low-power RISC-V processors and self-powered SoCs.

Yuchen Wang

Master’s Student

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

Feng Yan

PhD Student

My research interests include circuit design of analog front end for biomedical applications and sensor interfaces.

Kangkang Sun

PhD Student

My research interests include circuit design of analog to digital converter for biomedical applications and SAR ADC.

Bingjun Xiong

PhD Student

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.

Jian Guan

PhD Student

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