Dear group,
I have the following questions on testing a USB port for conducted immunity
1) USB extension cables are available in the consumer market. The USB 1.0 spec
limits the cable length to 5.0m. Therefor I believe that the conducted
immunity test is required even if the cable length of the DUT is less than 3m,
unles a restriction is made in the user manual.. Is that correct?
2) I tested conducted immunity using a CDN-S9 with home-made adaptors from DB9
to USB using 4 pins of the DB-9 and the screen connection. I assume that this
should give a representative result?
For information: this does not work for hi-speed USB because of the LPF in the
CDN.
3) Are CDN's for USB available? Or is it better to use an EM clamp?
kind regards,
Ton Bouw
