A high voltage multiplexer with rail to rail output swing for battery management system applications

Abstract

This work presents a dual channel 8:1 high voltage (HV) multiplexer (MUX) with a 3-to-8 decoder and 16HV switches for Battery Management Systems (BMS). Each HV switch consists of two pairs of sub-switches using n- and p-channel drain extended MOS devices with back to back body diode protection, respectively. The two pairs of sub-switches, connected in parallel and with dedicated gate drive signals, allow the HV MUX to have a rail-to-rail output swing and improved sampling accuracy. An experimental prototype is implemented using a 0.35µm 60V BCD process. The measurement results reveal that the maximum error of the HV MUX is ²0.2mV, and the power dissipation is below 2.3mW with a chip area of only 1.9 × 0.57mm2.