With the increasing development and application of high-tech automotive electronic products, how to solve the electromagnetic compatibility problem of automotive electronic systems, improve the reliability and safety of automobiles, has become a very important and urgent issue. However, as one of the methods to address electromagnetic compatibility issues, grounding design and ground offset testing are particularly important. Therefore, this article interprets grounding design and ground offset testing.

 

1、 Grounding design of the entire vehicle system

 

1. The significance of ground wire

 

The ground wire in a car is not just a contact point, it is a comprehensive system of automotive electrical systems, and its main functions include:

 

Provide current circuits for DC loads, AC loads, and transient loads, connecting the negative terminal of the battery or generator;

Provide voltage to sensors, communication systems, single ended digital inputs, etc;

Static shielding, isolating external RF radiation;

● Provide electrostatic discharge discharge and ESD protection;

The ground plane of the car antenna;

Reduce the voltage level and minimize corrosion.

 

2. Ground wire reliability

 

The reliability of the ground wire circuit is mainly determined by the following key factors:

 

The connection surface of grounding metal, including the connection between grounding plates and between grounding wires and grounding plates;

The influence of coating layer and lubricating oil on the conductive ground wire connection plate and its fasteners;

Potential corrosion;

Potential mechanical degradation.

 

3. The grounding symbols and grounding circuits on the car are shown below