EMC tests compare automotive electronics and IT products

This article will compare the electromagnetic compatibility testing and test items of electronic products in two different fields: automotive electronics and general electronic IT. The test methods and test equipment will be compared and analyzed. Electromagnetic interference can affect other electronic products around it to varying degrees. However, it is also a common electronic product. The requirements for electromagnetic compatibility between IT products and automotive electronic products are very different. However, in addition to performance, safety is the primary consideration. Once automotive electronic components fail due to electromagnetic interference, it is likely to pose a significant threat to the safety of users.

1、 Test project items and experimental purposes

In electronic products, electromagnetic compatibility testing is commonly referred to as EMC testing. The core of the test consists of two parts: electromagnetic interference capability, which mainly tests the electromagnetic interference emitted by the electronic product itself.. The second part is electromagnetic interference immunity, which mainly tests the electromagnetic interference immunity that may occur during the use of electronic products. For ordinary IT products, as electronic products and electromagnetic interference immunity are important testing items that affect customers' feelings about the use of the product itself, IT products have high performance requirements and diverse use environments, and manufacturers pay more attention to electromagnetic interference immunity testing. The purpose of the test is also clear to ensure that electromagnetic radiation does not occur in general life and that IT products have a significant impact on the user experience. In addition to electromagnetic interference immunity testing, the electromagnetic interference level testing of automotive electronic products is also very important. Because cars are highly electronic intensive carriers. In automobiles, in addition to multiple drivers such as starters, engines, spark plugs, and oil pumps, there are also dozens or even more than 100 microcontrollers. If the purpose of EMC testing for IT products is user experience, the purpose of EMC testing for automotive electronics is safety.

2、 Test standard comparison

There are still many EMC testing standards for some common IT electronic products, such as GB/T17618GB9254, GB/T17625, GB/T17626. CISPR22. EN55024. EN61000, etc. For some special IT electronic products based on general standards, there will be some special product standards, such as mobile phones, EMC, China Post and Telecommunications, and the International Telecommunication Organization will also participate in the preparation of standards. Generally speaking, YD/T1592.1, YD/T1595.1, YD/T1597.1, YD/T2583.14.ETSI300342.ETSI301498.ETSI300607, and so on.

For automotive electronic products, the preparation of international common standards is carried out by the International Standards Organization (ISO), the International Electrotechnical Commission Radio Interference Society (CISPR), and so on. Currently, the main standards are as follows: ISO11451.ISO11452.ISO7637.ISO16750.ISO10605.CISPR25, etc. Based on these international standards, automotive manufacturers often have a set of international standards that strictly implement the international standards EMC enterprise testing standards.

3、 Comparative test methods

Due to different testing standards, EMC testing methods for IT products and automotive electronics vary. IT electromagnetic interference sources generally come from electronic equipment such as nature, such as broadcasting and medical radio frequency equipment. 220V municipal and civil electricity. Therefore, EMC anti electromagnetic interference test is usually aimed at a wide range of tests. The most common type of interference is radiated noise. Electrostatic discharge interference has corresponding tests for continuous electromagnetic interference and radio frequency interference. The test method varies depending on the type of test. For example, in radiated noise immunity testing, some special test antennas will be used as interference sources to transmit the product under test, and testing will be conducted by setting different frequencies and field strengths. Some electrostatic tests will use an electrostatic discharge generator to conduct multiple discharge tests with different intensities. The most important is the performance parameters that affect the user experience. EMC testing of automotive electronic products is often much more complex and demanding. EMC testing of hardware often consumes a large amount of human and financial resources, sometimes accounting for more than half of the total cost of hardware development. The test is divided into two parts: emission test and immunity test. According to different coupling media, the emission test is divided into radiation tests. It is used to test the electromagnetic interference output in high and low frequency bands. Immunity tests generally include radiation immunity tests, magnetic field immunity tests, transient immunity tests, power supply immunity tests, and electrostatic discharge immunity tests. Compared to ordinary immunity requirements, immunity requirements are also higher and IT electronic products are much higher. Some test results will also be quantified and carried out strictly according to standards.

4、 Test Equipment Comparison

Both are relatively close to the type of test equipment. The EMC testing equipment for IT electronic products mainly includes quasi peak measurement receivers, average measurement receivers, swept frequency measurement receivers, artificial power supply networks, power absorption clamps, various current and voltage probes, etc. Automotive electronic EMC testing equipment mainly includes power receivers, spectrum analyzers, load simulators, artificial power networks, various current and voltage probes, and some upper computer monitoring equipment. The difference is that automotive electronics have stronger requirements and pertinence, higher test accuracy, and more diverse test functions. In particular, automotive electronic EMC load simulators typically require participation because automotive electronic control units typically have multiple loads. In order to better simulate its working state, it is necessary to equip different load simulators, which is also a difficulty in the entire process of EMC testing equipment.

5、 Conclusion

Through comparison, it can be found that for ordinary people, the purpose of IT to improve electromagnetic compatibility is not only to meet the requirements of laws and regulations, but also to better use the product and better user experience. GB9254 is also a mandatory national standard (mandatory indicator). IT product 3C has a mandatory requirement for certification, and failure to comply will be punished. Therefore, each manufacturer balances higher electromagnetic compatibility with lower production costs of the finished product. For automotive electronic products, electromagnetic compatibility is a necessary condition for functional safety. For manufacturers who ignore their importance, they not only lose the trust of their customers, but also are likely to be punished by law.