I have a puzzling situation with the AD8361ART (the 6 pin version). I had 3 in a row fail as nearly instantly as I can tell - that is as soon as I power up the board, the AD8361 is dead. The failure is exhibited by the Vrms pin going to +3.2V even with no RF input. the supply is 3.3V. Pdwn (pin 4) is connectd to ground. Fltr (pin 1) is connected to a 100 pF (other side of capacitor to +3.3V). Vrms (pin 1) is connected to a 100 pF to ground and to a National Semi ADC (ADC084S051). ADC datasheet says maximum 1 uA input current. ADC appears functional, i.e. it returns reasonable values when input is provided with AD8361 removed. After the first 2 failures, I thought maybe I had excessive RF going into it, so I removed the input capacitor, so pin 5 (RF in) is returned to ground through a 75 Ohm resistor. I then installed the third AD8361, but it failed immediately as well. The AD8361 is bypassed with 2x100nF ceramic chip capacitors and a 100 pf ceramic chip capacitor. Checked the supply voltage, it is 3.3V.
Any ideas as to what I may be doing wrong? So far all AD parts I've used have worked "as advertised". So I expect the AD8361 will also, once I find & correct whatever is wrong.
I checked the top code -- it is J3A so I'm pretty sure the part is right.