Got all the pieces for my LISN filters

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50 uH xfrms 1 50 uH xfrms 2

This past week I finally received the two 50 uH inductors for my CISPR16-spec LISN filter. As expected they´re thinner but a good bit longer than the 5 uH devices, and I had to rearrange the common- mode choke and the first set of Y-caps and their associated resistors. I also realized that I hadn´t added connections for the output to my DUT. (Or input from my DUT…power comes in but noise comes out, so both ports are inputs and outputs, really.)

The the 50 ohm noise output port I ended up putting footprints for everything. I figure I´ll test the impedance with the AP300 netowkr analyzer and then start adding stuff, and see if the Z curve deviates enough to fail spec. I have spots for an ESD diode, two low capacitance schottkys, L-C filters and an AC coupling cap. I didn´t try to add a limiter, though. I´m going to test a bunch of circuits with the 50 ohm setting on my oscopes and have them calculate RMS power, to see if it´s likely to damage the spectrum analyzer input.

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