A sub 1V CMOS bandgap reference with two diodes

Abstract

A small size, sub 1V CMOS bandgap voltage reference with the temperature coefficient (TC) of 12ppm/°C from 0°C to 100°C is presented in this paper. The proposed circuit offers several performance advantages over previous bandgap voltage reference circuits. Compared to a conventional structure, it achieves a smaller area by using only two diodes. Also, it can fulfil sub 1V reference voltage by using temperature coefficient of threshold voltage to generate a current proportional to absolute temperature. This is because TC of this current on proposed circuit is bigger than that of conventional structure. Detailed analysis of the proposed bandgap reference is provided, which is simulated using 0.35μm CMOS process. The proposed bandgap reference occupies an active area of 0.0067mm2. The simulation results are the voltage reference output voltage of 0.843V and an accuracy of ±0.08%.