Line Impedance Stabilization Network  (LISN)

DNB is a leading designer and producer of Line Impedance Stabilization Network (LISN) devices to support customers in conducted and radiated radio-frequency emission and susceptibility tests, as specified in various Electromagnetic compatibility (EMC)/EMI test.

A LISN is a low-pass filter typically placed between an AC or DC power source and the EUT (equipment under test) to create a known impedance and to provide a radio frequency (RF) noise measurement port. It also isolates the unwanted RF signals from the power source. In addition, LISNs can be used to predict conducted emission for diagnostic and pre-compliance testing.

Main Functions of a LISN

  • Stable line impedance. Providing a precise impedance to the power input of the EUT, in order to get repeatable measurements of the EUT noise present at the LISN measurement port.
  • Isolation of the power source noise. Preventing the high-frequency noise of the power source from coupling in the system. LISN functions as a low pass filter, which provides a high impedance to the outside RF noise while allowing the low-frequency power to flow through to the EUT.
  • Safe connection of the measuring equipment.  The stabilized impedance, the built-in low-pass filter function, and the DC rejection properties of the LISN measurement port make it easy to couple the high-frequency noise signal to the input of the measuring equipment.

DNB offers different types of lisn:

The DB4311 line impedance stabilization network (LISN) is designed to meet the requirements of CISPR 16-1-2, CISPR 22, CISPR 15, and ANSI 63.4 specifications. Both the 50Ω/50