A 0.9-V 22.7-ppm/°C Sub-Bandgap Voltage Reference with Single BJT and Two Resistors

Abstract

A CMOS sub-bandgap voltage reference (sub-BGR) with single BJT and two resistors is presented in this paper. The proposed sub-BGR structure generates the complementary-to-absolute-temperature (CTAT) voltage not only occupying small chip area and consuming nA-level current, but also achieving low sensitivity to the current mirror mismatches. The CTAT voltage is a scaled emitter-base voltage of a BJT and the proportional-to-absolute-temperature (PTAT) voltage is based on the stacking of ΔVGS of sub-threshold MOSFETs. The proposed sub-BGR circuit is implemented in a standard 0.18μm CMOS process, and the active area is 0.059 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The measured results show that the sub-BGR circuit can work with a supply voltage down to 0.9 V and the power consumption is only 66 nW. An average TC of 22.7 ppm/°C with a temperature range of -40 °C ~125 °C and a line sensitivity of 0.059%/V are achieved.