A New Bandgap Reference for High-Resolution Data Converters

Abstract

In this paper, a CMOS bandgap reference (BGR) for high-resolution data-converters is proposed and analyzed. The proposed BGR circuit is derived and modified from a recently developed low-voltage BGR. It combines two different branches of conventional BGR into one PMOS transistor, avoiding the matching requirement of the current mirror. The low temperature-susceptible current is used to generate high and low references for data-converters. This modified architecture is verified by a 0.35-um CMOS BGR circuit. In the demo design, the 2.7 V and 0.6 V voltage and 12 uA current references for a sigma-delta analog-to-digital modulator all obtain a temperature coefficient (TC) of about 20 ppm/K. With a tiny adjustment, the proposed BGR also has the potential to work at low supply-voltage.