A CMOS Voltage Reference Based on Mutual Compensation of Vtn and Vtp

A novel temperature-stable nonbandgap voltage reference, which is compatible with standard CMOS technology, is presented in this brief. No diodes or parasitic bipolar transistors are used. Based on mutual temperature compensation of the threshold voltages of nMOS and pMOS transistors, a temperature-insensitive voltage reference with significant reduction in temperature dependence of mobility is achieved without using subthreshold characteristics. The problem of a fixed voltage reference value is also avoided by different parameter design. Experimental results of the proposed voltage reference implemented with a 0.35-mu m CMOS process demonstrate that the output of the voltage reference is 847.5 mV, a temperature coefficient of 11.8 ppm/degrees C with a temperature range from 0 degrees C to 130 degrees C is obtained at 3-V power supply, a power-supply noise attenuation of 72 dB is achieved without any filtering capacitor, and the line regulation is better than 0.185 mV/V from 1.8-V to 4.5-V supply voltage dissipating a maximum supply current of 8 mu A. The active area of the presented voltage reference is 90 mu m x 120 mu m.