A 0.90–4.39-V Detection Voltage Range, 56-Level Programmable Voltage Detector Using Fine Voltage-Step Subtraction for Battery Management

摘要

A programmable voltage detector (PVD) for battery management is proposed to achieve the programmability of the detection voltage (V-DETECT). Thanks to the programmability, users can set an appropriate V-DETECT for battery management considering the operating voltage of the battery. For batteries including Li-ion and NiMH batteries, a PVD is required to achieve wide programmed V(DETECT )range from 1.0 to 435 V with a fine voltage step of +/- 42 mV. Furthermore, the power consumption of the PVD must he minimized since the PVD is always operating in battery management. To achieve both the target programmability of V(DETECT )and the low power consumption of the PVD, a programmable voltage reference (PVREF) using a fine voltage-step subtraction (FVS) method is proposed. The FVS is a combination of fine and coarse programming for the output of the PVREF, which achieves a fine voltage step and a wide programmable range of V(DETECT )achieving both a low temperature coefficient of V(DETECT )and low power consumption of the PVD. The measurement results of the PVD fabricated in a 250-nm CMOS process show a current consumption of the PVD of 1.2 nA at 3.5 V and a temperature coefficient of V(DETECT )of 0.28 nriV/degrees C. The PVD enables the widest programmable range of V(DETECT )from 0.90 to 4.39 V, fine V(DETECT )resolution of +/- 31.5 mV, and 56-level linear, monotonic programmability of V-DETECT.