Design of voltage reference with low sensitivity to process, supply voltage and temperature variations

A CMOS process-insensitive voltage reference generator, which is based on the weighted sum of thermal voltage and difference of threshold voltages, is presented. The voltage reference circuit uses high VTH and regular VTH transistors and produces reference level of 422mV. The proposed technique is analyzed theoretically and its results are compared with other methods. The circuit is designed and simulated in standard 180nm mixed mode CMOS technology for low-cost low-power applications. The circuit operates at minimum supply voltage of 1V with maximum drawn current of 577nA only. A temperature coefficient of 36ppm/°C is achieved with line sensitivity of 0.01%/V. The proposed reference generator exhibits PSRR of -60.34 dB and -37.09 dB at 100Hz and 1MHz, respectively.