Comparison of EMC test items for IT electronic products and automotive electronics

Interference signals will damage other electronic equipment around to a certain extent. However, the same electronic equipment, general IT products and automotive electronic products do have different requirements for EMC testing. However, in addition to the characteristics of automotive electronics, safety is the primary consideration. Once the vehicle electronic components fail due to interference signals, it is likely to pose a huge threat to the personal safety of users.

1、 Comparison of EMC test items and test purposes

In electronic equipment, EMC test is usually called EMC test. The key part of the test has two parts. The first part is the interference signal level, which is the key to detect the electromagnetic interference emitted by the electronic equipment itself.. The second part is electromagnetic immunity, which is usually used to test the immunity of interference signals that may occur in the use of electronic equipment. For common IT electronic equipment, electromagnetic interference immunity is the main test report that determines customers' feelings about the use of the product itself. Because of the high performance requirements of IT products and the changeable use scenarios, manufacturers will pay more attention to electromagnetic interference immunity test. The purpose of the test is self-evident, so as to ensure that the electromagnetic radiation will not cause significant damage to the sense of use of IT products in general life. For automotive electronic products, in addition to electromagnetic interference detection, its own interference signal level test is also very important. Because cars are the medium of high digital traffic. In addition to the starter, there are dozens of microprocessors, even more than 100 microprocessors, in cars, engines, spark plugs, in addition to oil pump and other controllers. If the purpose of EMC testing for IT products is customer experience, the purpose of EMC testing for automotive electronics is safe.

2、 Test standard comparison

There are still many EMC test specifications for some common IT electronic products. The sub-equipment has GB/T17618GB9254. GB/T17625. GB/T17626. CISPR22. EN55024. EN61000 and so on. For some special IT, according to the general standards, the electronic equipment will have some special product standards, such as the EMC test specifications for mobile phones. China Electric Power and its International Telecommunications Organization will also join the standard writing, Generally, there are YD/T1592.1. YD/T1595.1. YD/T1597.1. YD/T2583.14.ETSI300342.ETSI301498.ETSI300607.

However, for automotive electronic products, the International Standards Organization (ISO), the International Electrotechnical Commission Radio Interference Association (CISPR) and other core organizations are responsible for the writing of international general standards. At present, the main specifications are as follows: ISO11451.ISO11452.ISO7637.ISO16750.ISO10605.CISPR25, etc. According to this national standard, automobile manufacturers usually have a set of national standards and strictly comply with the national standard EMC testing standards.

3、 Comparison of test methods

Due to different test standards, EMC test methods for IT products and automotive electronics products are also different. IT interference signal sources generally come from electronic products such as nature, such as broadcasting, medical radio equipment, and 220 V mass electricity. Therefore, EMC anti-electromagnetic interference detection range is wide. The most common radiated noise interference. Electrostatic discharge has a clear detection of continuous interference signals and their radio frequency interference. The test standards vary according to different test types. If the radiated noise immunity test is conducted, some special detection antennas will be used as the interference source to send the test products, and the test will be conducted by setting different times and field strength. Some electrostatic tests will use an electrostatic discharge generator to conduct several discharge tests with different intensities. According to the most important technical parameters that endanger the customer experience. However, EMC testing for automotive electronic products is often much more complex and requires strict testing requirements. EMC testing of hardware usually takes up a lot of human and property resources, sometimes accounting for more than half of the total cost of hardware development. The detection is divided into two parts: transmission detection and anti-interference detection. According to the different coupling substances, the transmission detection is divided into radiation experiments. It is used to detect the interference signal derivation in high frequency and low frequency bands. Immunity test generally includes radiation immunity test, magnetic field immunity test, transient immunity test, power supply immunity test, electrostatic discharge immunity test, etc. The demand for anti-interference is also much higher than the general demand for IT electronic equipment. Some test results will also be quantified and strictly implemented.

4、 Test equipment comparison

Both are relatively close to the type of detection equipment. EMC test equipment for IT electronic products mainly includes quasi-peak measurement receiver, mean measurement receiver, sweep measurement receiver, human resource network, power absorption clamp, various current and voltage probes, etc. The EMC experimental equipment for automotive electronics mainly includes power receiver, spectrum analyzer, load simulator, human resource network, various current and voltage probes and some upper computer monitoring systems. The difference is that automotive electronics has stronger requirements and purposes, higher detection accuracy and more diversified test functions. In particular, the automobile electronic EMC load simulator usually needs to participate, because the automobile electronic control unit usually has multiple loads. In order to better simulate its running state, different load simulators must be equipped, which is also the problem of all load simulators EMC test equipment.

5、 Conclusion

Through comparison, it is not difficult to find that the effect of ordinary people's IT to improve electromagnetic compatibility is not only to meet the requirements of laws and regulations, but also to better use goods and better customer experience. GB9254 is a mandatory provision for 3C certification of IT goods in mandatory national standards (mandatory indicators), but it is punished to pass, so each manufacturer has to balance between higher electromagnetic compatibility and lower production costs of finished products. However, for automotive electronics, EMC testing is a necessary condition for functional safety. For manufacturers who ignore its importance, it will not only lack the trust of customers, but also likely to be punished by law.