How should the filter of the EPS driver circuit be designed?

The filtering design of the power device (IGBT/MOSFET) drive circuit in EPS is crucial for switching waveforms and system EMC. Design considerations:

1. Power supply decoupling: High-quality high-frequency decoupling ceramic capacitors (e.g., 0.1μF) and electrolytic or tantalum capacitors (e.g., 10μF) of a certain capacity must be placed near the power supply pins of the driver IC to provide transient high current and suppress power supply noise.

2. Drive signal filtering: A small resistor (gate resistor) can be connected in series between the output and gate of the driver chip, and a small capacitor can be connected in parallel between the gate and source to suppress ringing and slow down switching speed, but EMC and switching losses must be balanced.

3. Clean reference ground: An independent "drive ground" should be established for the drive circuit and connected directly and with low impedance to the source/emitter of the driven transistor using a Kelvin connection to avoid power ground noise interference.

4. Isolated power supply: For high-voltage side drive, an isolated DC-DC power supply module must be used, and a safety Y capacitor should be connected across the primary and secondary sides to provide a high-frequency noise loop.