A 0.45 V, 15.6 nW MOSFET-only sub-threshold voltage reference with no amplifiers

Abstract

An ultra-low voltage, low power, low line sensitivity MOSFET-only sub-threshold voltage reference with no amplifiers is presented. The bulk-driven technique is used and most of the transistors work in the sub-threshold operation, which allows a remarkable reduction in the minimum supply voltage and power consumption. Second-order compensation improves the temperature stability and the low sensitivity is realized by the difference between two complementary currents. Moreover, a trimming circuit is adopted to compensate the process-related reference voltage variation. The proposed voltage reference has been fabricated with 0.18μm 1.8 V CMOS process. The measurement results show that the minimum power supply voltage is 0.45V; the power consumption is 15.6 nW; the average temperature coefficient measured from −40 to 85°C is 59.4ppm/°C and the line sensitivity is 0.033% with power supply voltage ranging from 0.45 to 1.8 V. In addition, the chip area is 0. 013mm2.