A 31 pW-to-113 nW Hybrid BJT and CMOS Voltage Reference with 3.6% ±3σ-inaccuracy from 0○C to 170 ○C for Low-Power High-Temperature IoT Systems

Abstract

This paper proposes a low-power voltage reference generating 736 mV from 0 ○C to 170 ○C for low-power high-temperature IoT sensing systems. Using subthreshold current, a BJT diode develops a process-insensitive complementary-to-absolute-temperature voltage, and stacked CMOS transistors compensate the temperature sensitive by adding a proportional-to-absolute-temperature voltage. To maintain a reference voltage at high temperature, the circuit is designed considering pwell-to-deep nwell diode leakage. 76 samples from 3 different wafers, fabricated in a 180 nm process, show a ±3σ inaccuracy of 3.6% from 0 ○C to 170 ○C without any trimming. It consumes 31 pW at 27 ○C and 113 nW at 170 ○C from 0.9 V supply.