A 48 pW, 0.34 V, 0.019%/V line sensitivity self-biased subthreshold voltage reference with DIBL effect compensation

This paper presents a self-biased subthreshold CMOS voltage reference for low-power and low-voltage applications. To achieve near-zero line sensitivity and high PSRR, a compensation structure utilizing the drain-induced-barrier-lowering (DIBL) effect is proposed to sink a supply dependent current from the output branch of a self-biased CMOS reference, which cancels the bias current's dependence on the supply voltage due to the DIBL effect. Fabricated in a 0.18-μm CMOS technology, the measurement results demonstrate that the proposed circuit could operate under a minimum supply voltage of 0.34 V and generate a reference voltage of 147 mV, while consuming only 48 pW power. The PSRRs measured at 1 Hz and 10 kHz are -70.6 dB and -50.2 dB, respectively. For 39 measured samples, the mean line sensitivity is 0.019%/V in a supply voltage range from 0.34 to 1.8 V, and the average temperature coefficients before and after trimming are 64.81 and 10.06 ppm/°C in 0 100 °C temperature range, respectively. The total area of the voltage reference circuit is 0.0332mm².