A Nano-power Switched-capacitor Voltage Reference Using MOS Body Effect for Applications in Subthreshold LSI

Abstract

A nano-power CMOS voltage reference is proposed in this paper. Through a combination of switched-capacitor technology with the body effect in MOSFETs, the output voltage is defined as the difference between two gate-source voltages using only a single PMOS transistor operated in the subthreshold region, which has low sensitivity to the temperature and supply voltage. A low output, which breaks the threshold restriction, is produced without any subdivision of the components, and flexible trimming capability can be achieved with a composite transistor, such that the chip area is saved. The chip is implemented in 0.18 ?m standard CMOS technology. Measurements show that the output voltage is approximately 123.3 mV, the temperature coefficient is 17.6 ppm/oC, and the line sensitivity is 0.15 %/V. When the supply voltage is 1 V, the supply current is less than 90 nA at room temperature. The area occupation is approximately 0.03 mm2.