A low-power native NMOS-based bandgap reference operating from-55 degrees C to 125 degrees C with Li-Ion battery compatibility

Abstract

The paper describes the implementation of a bandgap reference based on native-MOSFET transistors for low-power sensor node applications. The circuit can operate from -55 degrees C to 125 degrees C and with a supply voltage ranging from 1.5 to 4.2 V. Therefore, it is compatible with the temperature range of automotive and military-aerospace applications, and for direct Li-Ion battery attach. Moreover, the circuit can operate without any dedicated start-up circuit, thanks to its inherent single operating point. A mathematical model of the reference circuit is presented, allowing simple portability across technology nodes, with current consumption and silicon area as design parameters. Implemented in a 55-nm CMOS technology, the voltage reference achieves a measured average (maximum) temperature coefficient of 28 ppm/degrees C (43 ppm/degrees C) and a measured sample-to-sample variation within 57 mV, with a current consumption of 420 nA at 27 degrees C.