A Low-power Bandgap Reference Voltage Source for Smart Grid Sensor System on Chip

Abstract

For smart grid sensor system-on-chips, traditional bandgap reference circuits have high power consumption, so low-power bandgap reference circuits must be designed that can meet their complex operating environments. This work designs a low-power bandgap reference voltage source for smart grid sensor system chips. Compared to traditional bandgap reference voltage sources, this design combines the high stability of the traditional BJT bandgap reference and the low power consumption characteristics of the sub-threshold bandgap reference, and they are controlled by a digital signal. In normal mode, only conventional BJT bandgap reference (main bandgap) works, and only the sub-threshold low-power bandgap reference (auxiliary bandgap) works in sleep mode. Realized in UMC 55nm ULP CMOS process, the normal mode power consumption is 65 µ W, the temperature coefficient (TC) is 7.7ppm/°C, and the PSRR is - 78dB; After switching to the sleep mode, the power consumption is 2.38 µ W with a TC 1.45ppm/°C. It provides a stable 1.2V reference voltage when the power supply voltage is 1.6V to meet the demand for stable power supply of the on-chip smart grid sensor system under complex working conditions.