Hello. I have built a test circuit for the AD831 as per the single voltage supply on the data sheet.
I am feeding the RFin with 7Mhz @ 20mv LO with 3Mhz @ 10mv and a 9V supply.
The chip seems to get quite hot is this normal?
Regards - Paul
Yeah, this is normal for the AD831. It has a supply current of 100 mA nominal on a 9V supply, this is almost 1Watt of power it must dissipate from the PLCC package, which has no ground paddle to act as an efficient heat sink.
You may want to try putting thermal paste between the bottom of the DUT and the board. This may conduct some of that heat away from the board to the PC board better.
Hope this helps,