A 19-30ppm/°C Temperature Coefficient Sub-Nanowatt CMOS Voltage Reference with 10-µA Sourcing Capability

Abstract

The Internet of Things (loT) is developing rapidly, and energy harvesting (EH) provides the power source impetus for it. Still the energy collected from EH is generally underfed, which obliges EH powered modules to achieve low power consumption as much as possible. Hence, the growth of low voltage and low quiescent current designs are pushed forward. For applications with sub-10µA under low-supply (200-300mV), such as sensors for monitoring, SRAM [1], designing an additional regulator is overburdened and one solution is the voltage reference (VR) integrated with output buffer. Whereas the added buffer brings extra area and power consumption (e.g., microwatt), the mismatch substantially degrades the temperature coefficient (TC). Therefore, a sub-nanowatt VR with current sourcing capability is of momentous significance. Besides, supposing that the power consumption of the designed VR is in the order of picowatt, and due to the process restraint, the subsequent gates of MOS transistors connected to the VR output have leakage current of picoampere, it will directly cause the VR to be shut down, needless to mention the microampere loading capability. However, the existing CMOS voltage references (CVRs) hardly source current [2]–[6].