Voltage sensing device for an individual cell of a group of battery cells

摘要

A voltage sensing device with which high-precision voltage sensing is possible without the need to obtain a unique correction constant for each device. A pair of voltage input nodes NCk and NCk-1 is selected from voltage input nodes NC0-NCn in switch part 10, and they are connected to sensing input nodes NA and NB in two types of patterns with different polarity (forward connection, reverse connection). Sensing input nodes NA and NB are held at reference potential Vm by voltage sensing part 20, and current Ina and Inb corresponding to the voltage at voltage input nodes NCk and NCk-1 flows to input resistors RIk and RIk-1. Currents Ina and Inb are synthesized at different ratios in voltage sensing part 20, and sensed voltage signal S20 is generated according to the synthesized current Ic. Sensed voltage data S40 with low error is generated according to the difference between the two sensed voltage signals S20 generated in the two connection patterns.