A sub-1V supply CMOS voltage reference generator

Abstract

An integrated sub-1V voltage reference generator, designed in standard 90-nm CMOS technology, is presented in this paper. The proposed voltage reference circuit consists of a conventional bandgap core based on the use of p-n-p substrate vertical bipolar devices and a voltage-to-current converter. The former produces a current with a positive temperature coefficient (TC), whereas the latter translates the emitter-base voltage of the core p-n-p bipolar device to a current with a negative TC. The circuit includes two operational amplifiers with a rail-to-rail output stage for enabling stable and robust operation overall process and supply voltage variations while it employs a total resistance of less than 600?K O. Detailed analysis is presented to demonstrate that the proposed circuit technique enables die area reduction. The presented voltage reference generator exhibits a PSRR of 52.78?dB and a TC of 23.66ppm/degrees C in the range of - 40 and 125 degrees C at the typical corner case at 1?V. The output reference voltage of 510?mV achieves a total absolute variation of +/- 3.3% overall process and supply voltage variations and a total standard deviation, s, of 4.5?mV, respectively, in the temperature range of - 36 and 125 degrees C. Copyright (c) 2011 John Wiley & Sons, Ltd.