I am using the ADG1434 quad switch and we are having what appear to be ESD failures. Using a curve tracer, we can see 20-25uA @ 0.5V between pin 1 and VSS on two different failed parts. We have one more failed part that is closer to a dead short between pin 1 and VSS. Pin 1 was where the ESD event (+/-8kV direct) occurred.
We were using the 0402ESDA-MLP made by Cooper Bussmann, which have a working voltage of 30V and a clamp voltage of 35V. They are performing to their datasheet during our tests. The ADG1434 is biased at +/-16V and they fail more often when they are ON (ie. the switches are biased), as opposed to OFF (VDD = VSS = 0V). I am assuming that I need to find an ESD diode that is bidirectional, Working voltage of 15V (to meet our EIA_232_F spec), with a clamp voltage around 18V-19V so that we don't violate the abs. max Vdd to Vss of 35V. I'm having trouble finding something like this in a reasonable size package (0402 or 0603).
What is the ESD rating on the ADG1434? Any other event types that could cause a latch up that would damage the ADG1434?
Thanks for your time!