A 36pW CMOS Voltage Reference With Independent TC and Output Level Calibration for Miniature Low-Power Systems

We propose a low-power voltage reference of which temperature coefficient (TC) and absolute output level are independently adjustable. It enables to optimize TC without sacrificing output level distribution, compared with the previous works. The design provides the separate control by employing a DAC using diode-connected PFETs and an analog multiplexer for the output level trimming, in addition to biasing current control for TC improvement. Fabricated in a 180 nm CMOS process, the proposed circuit generates a stable reference voltage of 192 mV on average, with a $\pm 3 \sigma$ inaccuracy of 8.8 mV from 0 to $75^{o}\mathrm{C}(10$ samples), while consuming only 35.8 pW at 0.6 V and $25^{o}\mathrm{C}$.