Hi Jim My circuit can simulate after I flip the amplifier from + to -.
However, I have a new problem with the Sample/Hold circuit design.
I tried to join the newsgroup you posted, but I don't remember my ISP username/password. So I post a copy of an article with the circuit that I want to simulate in the following website:
Could you check if there is something wrong with the circuit or if there is something wrong with the values that I use?
I would really appreciate your help
Thanks