A highly integrated analog front-end combining level shifter, programmable gain amplifier, and low-pass filter for automotive BMS

This brief presents a highly integrated analog front-end (AFE) for automotive battery management systems (BMS). The proposed AFE combines level shifter (LS), programmable gain amplifier (PGA), and low-pass filter (LPF) functions into a single switched-capacitor architecture. Additionally, an offset cancellation scheme is employed to cancel the amplifier offset. Designed in a 130 nm BCD process, the proposed circuit utilizes capacitively-coupled inputs along with high-voltage (HV) switches realized with 5 V MOS devices placed in isolated N-Buried layer (NBL) pockets to handle input voltages up to 100 V. The circuit simultaneously provides programmable gain from 1 to 5 times and first-order low-pass filtering with a 1.6 kHz cutoff frequency for anti-aliasing. This three-in-one integration significantly reduces component count, system complexity, and power consumption compared to traditional cascade approaches. Designed for 125 kS/s operation, the AFE enables high-precision cell voltage monitoring with over 16-bit effective number of bits (ENOB). Operating at a 5 V supply, the AFE consumes only 330μ A (not including the ADC), making it a highly efficient solution for electric vehicle BMS applications.

Subjects

analog-to-digital converter

Battery management system

level shifter

low-pass filter

programmable gain amplifier

DDC Class

537: Electricity and Electronics

Options

A highly integrated analog front-end combining level shifter, programmable gain amplifier, and low-pass filter for automotive BMS