A 0.6V Temperature-stable CMOS Voltage Reference Circuit with Sub-threshold Voltage Compensation Technique

Abstract

This paper presents a CMOS reference circuit which can work properly under the near-threshold voltage of 0.6V. It is based on the temperature characteristic of NMOS&PMOS transistors in the sub-threshold region. The temperature curve of the NMOS quasi-PTAT current and the PMOS quasi-PTAT current can be adjusted to have the same slope factor. Thus a temperature-stable reference voltage can be achieved by subtracting the quasi-PTAT voltage generated by the NMOS and PMOS circuits. It can be used under the supply voltage of 0.6V, under which a traditional bipolar-based band gap reference cannot work properly. The circuit is designed and implemented in SMIC 65nm CMOS process. It provides a nominal reference voltage of 154mV, a average temperature coefficient of 87 ppm/°C in [-10°C ∼80°C] under a 0.6V supply voltage. The total power consumption is 60µW and the chip area is 345um *182 um.