ESD problems --> good filter components

[MrMetthew]

Hey guys,

I have some problems. The situation is a test rig where dut's are plugged in with a cable. Problem is that the dut's often are charged :s. Resulting in incredible spikes everywhere in my circuits. The spikes are very short (200ns) and very high (up to 400v Vptp).

Without going into to much detail there are (among other things) mosfet on those lines. The mosfets can pull these lines to the ground. These mosfets are getting destroyed by the spikes. I cant just add some capacitors to the line because it would be hard for the mosfets then to pull them to the ground reference if you know what I mean.

Can you guys recommend me some good filter components for this ? They have to be extremely fast acting, see the picture of one of the captured spikes. They also need to be able to withstand a couple of hundred volts. I have problems finding something that can react fast enough. Maybe I am focusing on the datasheets to much of standard anti esd components and deeming them unworthy because of datasheet conduction speeds.

I have not much experience in the subject, that's why I would really appreciate some advice!

BTW: Sorry for being so vague but if I have to explain the system in detail I would be typing 2h+. I can still do that if you guys want.. Also my brain is kinda fried after 10h straight of debugging this :p

[MrMetthew]

image

[MagicSmoker]

TVS diodes are plenty fast enough, and appropriate for the job.