Ultra‐low power voltage reference with 40 μA maximum load current for passive sensor systems

Abstract

An ultra-low power, low temperature coefficient voltage reference generator used for nanowatt-level passive sensor systems is presented. The voltage reference configuration, based on a voltage reference generating circuit embedded in the feedback loop, realises an average reference voltage (VREF) of 837.2 mV and 40 μA maximum load current. The temperature coefficient of VREF is compensated by a saturated diode-connected the positive channel Metal Oxide Semiconductor (PMOS) and a proportional to absolute temperature current. For supply voltages ranging from 0.86 to 3 V, this proposed voltage reference simulated in 55 nm a Complementary Metal Oxide Semiconductor (CMOS) process consumes an average current of 10 nA at room temperature and achieves a minimum temperature coefficient of 8.1 ppm/°C from −40°C to 125°C. The mean line sensitivity is 0.17%/V and the coefficient of variation is 2.1%.