一、Scheme protection circuit diagram

二、Application background

1. Body electronic control system (including lighting instructions and windows, wipers, etc.)

2. Exhaust gas recirculation system, cruise system and air conditioning system

3. Electronically controlled fuel injection system, electronically controlled transmission system

4. Anti-lock Braking System (ABS)

5. Anti-skid control system (ASR)

三、Explanation of the plan

1. This solution uses semiconductor discharge tubes with very low residual voltage to effectively protect RS485/232 chips and meet surge standards such as IEC61000-4-5.

2. The reaction time of the semiconductor discharge tube in the scheme is ns level, which can prevent surge and anti-static, and meet the static electricity standards such as IEC61000-4-2.

3. The junction capacitance of the semiconductor discharge tube in the scheme is small, the signal is not attenuated, and the transmission of the control line is not affected.

4. This solution uses the same type of semiconductor discharge tube in differential mode and common mode, and there is no dead angle for protection.