A high power supply rejection radio voltage reference for energy harvesters

This paper presents a design of a high power supply rejection radio (PSRR) bandgap voltage reference (BGR) which is used in the processing circuit of energy harvesters. The improvement of the PSRR of the BGR is implemented through adding a pre-regulating circuit to improve the low frequency PSRR and a low pass filter to improve the high frequency PSRR. The BGR is verified by using SMIC 0.18um 1P6M process. The supply voltage is 2.5 V and the BGR provides a reference voltage of 1.19 V. The simulation results show that the PSRR at 1MHz is about -40 dB and the PSRR at DC region is about -125 dB. This circuit also enhances the line regulation performance. A stable output voltage can be obtained when the supply voltage varies from 2.5 V to 6 V. The overall current consumption of this design is less than 50μA.