An ultra-low power CMOS subthreshold voltage reference

A voltage reference circuit operating with nanopower consumption has been proposed in this paper. There are only two current branches in the core circuit. The simulation results show that the average output reference voltage is 0.257V, and the line sensitive is 6.9ppm/V in a supply voltage range from 0.6V to 2V. Resulting from the approximated consideration of body effect, a temperature coefficient of 2.5ppm/°C is achieved in a temperature range from -20°C to 80°C. The power consumption is minimized to 1.5nW at room temperature while the power supply rejection ratio is -40dB at 100Hz and -29dB at 10MHz.