GW Instek

EMI FAQs 3

31. Does GW Instek have EN55025/ISO16750 automotive conducted EMI test kit?

The frequency band for automotive electronics testing in the conducted section is from 10 kHz to 108 MHz and the test must be collocated with a dedicated DC LISN. GW Instek GLN-5040A is a LISN that uses AC power and cannot be used for conducted EMI measurement of automotive electronics. However, GSP-9330 can conduct the above-mentioned test while collocating with a DC LISN of other brands.

32. The EN55015 regulation primarily defines the conducted (CE) test for LED luminaires. What are the test regulations for radiated test (RE)?

The radiated (RE) test regulation EN55015 is mainly defined in the test range of 30MHz ~ 300MHz. For different test sites, the defined test regulations will be different. The test regulations of 3m can be set by referring to the test lead of EN55022A. If the test regulation of 10m is adopted, refer to the test lead setting of EN55022B.

Frequency Range, MHz	QP limits (dBuV)	AVG limits (dBuV)
Frequency Range, MHz	3m distance	10m distance
30 ~ 230	40	30
230 ~ 300	47	37

33. What are the test regulations for EN61000-6-4?

The test regulations of EN61000-6-4 are general standards used to define the EMI standard under industrial environments, which is the standard of Class A. Its regulations are the same as those of EN55011A. The regulations for conducted and radiated tests are as follows:

Frequency Range, MHz	QP limits (dBuV)	AVG limits (dBuV)
0.15 ~ 0.5	79	66
0.5 ~ 30	73	60
EN61000-6-4 Conducted test regulations

Frequency Range, MHz	QP limits (dBuV)
30 ~ 230	40
230 ~ 1000	47
EN61000-6-4 Radiated test regulations

34. Can GSP-9330 set a Limit Line of CISPR 25, a Limit Line with breakpoints?

GSP-9330 cannot perform editing, but the GSP-9330's dedicated PC software SpectrumShot can perform editing.

This PC software must be collocated with the NI VISA driver. Please download it from the NI website.

35. What is the QP time constant defined in the CISPR 16 Regulation?

CISPR 16 defines the regulations for EMI test equipment, as shown in the following table, which is the Receiver or spectrum analyzer for EMI measurement. The regulation characteristics must meet the requirements of the parameters. It mainly defines which Detector to be used in the measurement bandwidths and the corresponding time constants.

For an explanation of the various Detector differences, please refer to the video “Peak, Average and QP detectors” on YouTube.

36. What is CE certification?

CE (Conformité Européenne) represents a product that can comply with the relevant directives of the European Commission such as safety, health, environmental protection and other related directives. It is a self-certification program. According to EU regulations, if the product is to be sold to the EU, the product must pass the CE certification and show a CE mark on the product.

37. The difference between EMC certification and LVD certification.

Both EMC and LVD are test items under CE certification.

EMC is primarily defined in the Electromagnetic Compatibility Directive. The main test is to test whether the product is likely to cause interference (electromagnetic interference, EMI) and the ability to resist interference (electromagnetic susceptibility, EMS) during RF signal analysis.

LVD (Low Voltage Directive) is a directive under CE certification that specifies the hazard prevention requirements of electrical equipment under direct action, such as overcurrent protection, overvoltage protection, contact protection, over temperature, radiation, mechanical and non-mechanical factors, etc. . The scope of application of the directive is to use electrical products with a voltage between 50V and 1000V and a voltage between 75V and 1500V (voltage refers to the input or output voltage of the electrical product, and does not include the voltage of the internal circuit of the product).

38. What is the complete EMC test content?

Electromagnetic compatibility (EMC, ElectroMagnetic Compatibility) consists of two parts, electromagnetic interference (EMI) and electromagnetic susceptibility (EMS). They mainly define that electronic products in the working environment can not interfere with the normal operation of other electrical products, and does not emit interference that other products cannot resist.

EMI focuses on the interference emitted by the device outward, while EMS focuses on interference emitted from external electronic products that interferes with the product. There are usually the following tests.

39. What are the test paths for the radio frequency (RF) part of the EMC test?

The path refers to the signal transmission methods of the DUT. There are usually two parts, which are transmitted through the wire or through the air. Therefore, in terms of test paths, both EMI and EMS tests include both conducted and radiated test paths, as shown below. In the EMC regulations, corresponding test regulations are also developed for these four situations.

The main details of the tests are shown in the table below.

Conducted EMI test (Conducted Emission)	The power cable of the DUT is connected to the simulated power supply impedance network (LISN) and the radio noise level of the product to be tested is transmitted to the measurement receiver to obtain the noise level.
Radiated EMI (Radiated Emission)	Under normal use, the radio of the DUT is received over the air to an antenna of 3M or 10M away, and then it is transmitted to the measurement receiver to obtain the noise level.
Conducted EMS test (Conducted Susceptibility)	The noise test mixed in the power cable and the control cable is used to test the interference of the DUT after coupling the noise and the power source, such as using an impulse test.
Radiated EMS test (Radiated Susceptibility)	Simulate the interference of the DUT exposed to electromagnetic waves, and transmit the required RF power by the antenna. The common test range is 80MHz~1GHz, and 1V/m ~ 10V/m with AM 80% modulation signal.

40. Why can't spectrum analyzers or EMI receivers observe transient interferences of electrostatic discharge?

Because spectrum analyzer and EMI receiver are narrow-band sweep receivers, they only receive energy in a certain frequency range at a certain time. Transient interference of electrostatic discharge is a kind of pulse interference, and its spectral range is very wide, but the time is very short. When an instrument produces transient interference, it is only a small part of its total energy that cannot represent the actual interference situation.

41. What regulations do I need to meet signal receiving equipment used in testing EMI?

Signal receiving equipment for EMI testing is typically EMI receiver or EMI spectrum analyzer, which receives signals coming in through the antenna, probe or cable. Regardless of the EMI receiver or EMI spectrum analyzer, both must meet the following regulations:

- ±2dB absolute amplitude accuracy
- Filter (-6dB) that meets CISPR requirements, as shown in the table below:

Frequency band	Filter (6dB)
9k ~ 150kHz	200Hz
150kHz ~ 30MHz	9kHz
30MHz ~ 1GHz	120kHz
1GHz ~ 3GHz	1MHz

- Support Detector for EMI: Max Peak (PK+), Quasi-Peak (QP), EMI Average (EMI-AVG), RMS Average (RMS-AVG)

42. How do you edit the limit line of SpectrumShot?

You can edit the limit line from the Setting of SpectrumShot software. The block that selects the limit line has an Edit function, which has the limit line that the current software provides. When users want to add or edit a new limit line, this function can be utilized to complete the requirement quickly.