A novel precision CMOS current reference for IoT systems

This paper presents a low-voltage and low-power CMOS precision current reference circuit, which leads to high current stability to temperature and supply variation. By exploiting the dependence of the threshold voltage and its temperature characteristics on the transistor size, a new temperature compensation method is proposed to greatly improve the temperature stability of current references and reduce its area. In addition, a novel topology is proposed to drastically enhance the supply voltage stability of current references and further improve its temperature stability. Based on a 0.18 mu m standard CMOS process, post-layout simulation results show that the proposed design achieves a mean temperature coefficient (TC) of 15.71 ppm/degrees C over the temperature range of -20 degrees C to 120 degrees C at a 0.6 V supply voltage. The line regulation (LR) is 0.04%/V over the supply voltage range from 0.6 V to 1.8 V at 27 degrees C. The power consumption is 207 nW at a 0.6 V supply voltage, and the active area is 0.00808 mm(2).