How to resist EMI in EPS analog sampling?

Analog sampling in EPS (such as battery voltage and temperature) is highly susceptible to EMI, leading to decreased accuracy. EMI mitigation measures include:

1. Sensor-end filtering: Adding an RC low-pass filter near the sensor (such as a voltage divider resistor or thermocouple) to remove high-frequency noise.

2. Signal transmission shielding: Using shielded twisted-pair cables to transmit analog signals, with the shield grounded at a single point on the sampling board.

3. Sampling circuit layout isolation: Placing the sampling op-amp and ADC in a "clean area" on the PCB, away from power components. Grounding the sampling traces.

4. Differential sampling and common-mode rejection: Using differential input op-amps and high CMRR devices such as instrumentation amplifiers to suppress common-mode noise.

5. Power supply decoupling: Providing an extremely clean analog power supply for the sampling op-amp and ADC, using low-noise LDOs, and placing multiple decoupling capacitors of different values.

6. Digital filtering: After ADC sampling, using algorithms such as moving average and median filtering in the software to further suppress noise.

7. Using isolated op-amps: Using isolated op-amps for high common-mode voltage or long-distance sampling.