A 0.6-V Minimum-Supply, 23.5 ppm/°C Subthreshold CMOS Voltage Reference With 0.45% Variation Coefficient

In this brief, a low-voltage low-temperature- coefficient (TC) subthreshold CMOS voltage reference (CVR) is presented. The proposed CVR employs the ΔV
_GS
of different-threshold and same-threshold nMOS transistor pairs to generate the complementary-to-absolute-temperature and proportional-to-absolute-temperature voltages, respectively. Low TC with small variations and high power supply ripple rejection (PSRR) are achieved. The proposed design is fabricated in a standard 0.18-μm CMOS process. It measures an average reference voltage of 218.3 mV with a deviation of 0.97 mV and variation coefficient of 0.45%. It achieves an average TC of 23.5 ppm/°C for a temperature range of -40 °C to 125 °C. The measured PSRR is -66.4 dB, -42.4 dB and -42.3 dB at 10 Hz, 1 kHz and 10 MHz, respectively. The measured line sensitivity is 0.40%/V for 0.6 V to 2.0 V supply. The consumed power is 30.5 nW at 0.6-V supply.