High Voltage CMOS Bidirectional Current Sensor for Battery Moniroring in Portable Devices

摘要

This investigation demonstrates a high-accuracy bidirectional high-voltage (HV) current sensor fabricated by CMOS technology. Besides Noise filter, Sense stage, and Controller, the proposed current sensor is featured with a Switching Network composed of transmission gates, which is able to steer the direction of the current. A digital feedback loop comprises Controller generating a pair of digital signals to Switching Network such that the direction of the current is detected real time. The area of the proposed sensor on silicon is 1173×664 um2 using 0.5 um high-voltage CMOS process, which is very compact to be easily integrated in any portable devices demanding a current monitoring function. The sensing voltage error is 0.7 % by the physical measurements, where the input voltage range is 8~14 V, and the current sensing range is -3~ 3 A.