On 5/8/08, Martin <
martin@...> wrote:
> I have an analog circuit that has a (normally) negative polarity DC
> feedback signal. I'd like to change the gain of the circuit digitally,
> so I'd like to use a digital pot. The problem is that a digital pot can
> only take signals between VEE and VDD - most usually probably 0v to 5v.
>
> My rails are +5/0/-5 and my feedback lies somewhere between 0 and -5.
So? Who stops you to supply your potentiometer driver (assuming it's a
PIC) between 0 and -5V ?
> Has anyone encountered a digital pot that can either take a 10v supply,
> or has level shifters on the digital lines? I think I might be able to
> use a CD4052 with discrete resistors, but then it's a 16 pin chip I have
> to put on the board.
>
> Any ideas?
>
> -
> Martin
> --
>
http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
>
http://mailman.mit.edu/mailman/listinfo/piclist>
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
