An Operational Amplifier with High EMI-Immunity in Battery Management System for New Energy Vehicle

A CMOS fully differential push-pull (FDPP) operational amplifier (Op Amp) is proposed with high gain and electromagnetic interference (EMI) immunity. The operating principle of this work is described and the structure is provided. The proposed Op Amp focuses on the application of new energy vehicles and it helps improve circuit robustness and reliability. The circuit is designed in $0.35\mu \mathrm{m}60\mathrm{V}$ Bipolar-CMOS-DMOS (BCD) Technology with a supply voltage of 5V to achieve 86dB gain, with a 10° phase margin, unity gain frequency (UGF) of 12MHz, static power consumption of 3mW, and full swing input. Measurements of EMI-induced input offset confirm the circuit simulation. The input offset voltage is only 0. 2mV with 2. 4GHz 1Vpp EMI. After simulation verification, this Op Amp can be used for BMS chips of new energy vehicles.