I have used STD1HNC60 but I notice they have been discontinued by
RS. I recall low capacitance with decent transconductance were key
considerations.

The smaller the better, probably. Check out those with the lowest
current capacity and voltage limit you can get away with.

Keep in mind that your CCS must be stable, and work well beyond the
bandwidth of the amp. Patrick's presumably static measurements are
not worth much.

cheers, Ian

wrote in message
...
I'm wanting to use a FET as a current sink for a differential
longtail.
This will be a balanced input front end using a 6922 with about
a -60VDC on the tail.
All the FETS I have around here seem to have the reverse
protection diode built in.
Can anyone recommend a good part number for this? I've been
experimenting with
the MJE350 bipolar part, but I want to try the FET and see if it
will be more stable
with temp and better PSRR. Any ideas appreciated.

Thanks!
RonL