Line Impedance Stabilization Networks (LISN) – Basics and Overview

Posted by Batter Fly 28/01/2022 0 Comment(s) 18363 Test & Mesure,

A line impedance stabilization network (LISN) is a device used in conducted and radiated radio-frequency emission and susceptibility tests, as specified in various EMC/EMI test standards. LISN are also sometimes referred to as artificial networks (AN) or artificial mains networks (AMN).
In conducted emission measurements, LISN are inserted into the supply lines of the equipment under test and provide an RF output to measure conducted emissions.
In many other test set-ups, LISN are inserted into the EUT supply lines just for the purpose of creating a defined source (supply) impedance.
The output impedance of a power supply (source) is hardly ever known and varies from source to source. EMC testing requires a well-defined and repeatable set up, which is created by placing a LISN in series with the source. The equipment under test does no longer see the output impedance of the source, but instead the specified impedance of the LISN.

How does it work?

If you want to measure conducted noise emissions, you could do it as simple as below:

It is definitely possible, to measure conducted emissions produced by the EUT, using this simple set up. However, the amplitude of the conducted emissions will be influenced by the impedance of the source. The source impedance is part of a voltage divider in the overall system and has a significant influence on the amplitude of the measured amplitude of the conducted emissions. As it is necessary to get the same results for the same EUT in any lab, anywhere, it is necessary to remove the impedance of the supply source from the equation.
The picture below shows how a LISN is inserted into the setup, in order to provide a defined impedance for the conducted emissions travelling on the supply lines of an equipment under test:

A LISN can be connected to any power supply and provide the same voltage and current capability as the power supply at the EUT terminals. However, the source impedance of the LISN is specified by EMC standards and enables repeatable conducted emission measurements in any laboratory.

Download the free application note (PDF file)

Model	Impedance	Frequency Range	Path	Maximum Current	Maximum Voltage	EUT Socket	Additional Features
TBL00705-2	50Ω // 0.7µH	10 Hz – 200 MHz	2	5 A	0 - 60V DC	4 mm banana	-
TBL0110-2	50Ω // 1µH	30 Hz - 500 MHz	2	10 A	0 - 60V DC	4 mm banana	-
TBL0225-2	50Ω // 2µH	10 Hz - 200 MHz	2	25 A	0 - 60V DC	4 mm banana	-
TBOH01	5µH // 50Ω	100 kHz – 110 MHz	1	10 A	200V	4 mm banana	-
TBL0550-1	5µH // 50Ω	100 kHz – 150 MHz	1	50 A	0 - 60V DC	Phoenix High current	-
TBL05100-1-B	50Ω // 5µH + 1Ω	10 kHz – 400 MHz	1	100 A	1000V DC / 500V AC	Phoenix High current	Configurable topology
TBLM02	N/A (Separator)	9 kHz - 110 MHz	Separator	N/A	N/A	BNC	CM/DM Separator
TBL5008-2B	50Ω ║ (50µH + 5Ω)	9 kHz - 30 MHz	2	8 A	250V	Country specific	Artificial hand Switchable PE Independent BNC
TBL5008-2C	50Ω ║ (50µH + 5Ω)	9 kHz - 30 MHz	2	8 A	250V	Country specific	Artificial hand Switchable PE Limiter/highpass
TBL5016-1	50Ω // 50µH (+5Ω)	9 kHz – 100 MHz	1	16 A	250V AC/DC	Phoenix High current	Configurable topology
TBL5016-2B	50Ω ║ (50µH + 5Ω)	9 kHz - 30 MHz	2	16 A	250V	Country specific	Artificial hand Switchable PE Independent BNC
TBL5016-2C	50Ω ║ (50µH + 5Ω)	9 kHz - 30 MHz	2	16 A	250V	Country specific	Artificial hand Switchable PE Limiter/highpass
TBL5016-3-EU	50Ω ║ (50µH + 5Ω)	9 kHz - 30 MHz	3	16 A	540V / 260V	CEE/IEC60309	Artificial hand Switchable PE
TBL5032-3-EU	50Ω ║ (50µH + 5Ω)	9 kHz - 30 MHz	3	32 A	540V / 260V	CEE/IEC60309	Artificial hand Switchable PE
TBL50100-1	50Ω // 50µH	9 kHz - 100 MHz	1	100 A	250V AC/DC	Phoenix High current	-
TBLDC32-2	150Ω (CM/DM)	9 kHz - 30 MHz	2	32 A	1000V DC	4mm safety	Rotary switch (A, B, CM, DM)