• Wide frequency range: 9 kHz - 30 MHz
• Coils matched to application
• Air core coils
• Individually calibrated

Com-Power LI-215A Application

The LISN provides input power line impedance to the equipment under test (EUT) that is constant and inde­pendent of the line impedance of the external power source during conducted emissions testing.

In addition to providing constant power line imped­ance, the LISN functions as a low pass filter for the power to equipment under test. It prevents any radio frequency noise on the external power line from reach­ing the equipment under test (EUT).

Other functions of the LISN include; providing 50 Ohm connection to the spectrum analyzer to measure EMI voltage generated by the EUT and blocking mea­surement of EMI voltage emanated by other equipment connected to the external power source.

The insertion loss of the LISN may be significant at low frequencies. Therefore, at frequencies below 400 kHz, the insertion loss correction factor must be added back to the spectrum analyzer reading. The LISNs frequency vs insertion loss characteristic table for each line is shipped with each unit for this purpose. The impedance data shipped with each LISN is not used in measurement calculations. However, periodic calibration of the LISN impedance is necessary to ensure accurate conducted emissions measurements.