2.3 ppm/°c 40 nW MOSFET-only voltage reference

Abstract

A MOSFET-only sub-bandgap voltage reference at less than 50 nW and with very low temperature coefficient is introduced. It consists of a threshold voltage extractor circuit and a proportional to absolute temperature voltage generator, using no resistors. The behavior of the circuit is analytically described, a design methodology is proposed and simulation results for a 0.13µm CMOS process are presented. It allows a reference voltage below the bandgap, 625 mV in this design example, achieving a temperature coefficient of 2.3 ppm/ • C for the -40 to 125 • C temperature range. The circuit consumes 40 nW at 27 • C and under 1.2 V supply, being the implemented silicon area 0.0099 mm 2 .