Re: servo DAC question

>
> From: bfp@...
>
> hello all I was just wondering
> what would be the minimum resolution requirement for a servo control DAC
> 8,10,12 bit?
> most of the commercial boards Ive seen are using 12 or 13 bit DACs,8 bits
> would only give 256 voltage steps,kind of rough,could a software PID
> loop toggle between two values fast enough to smooth this out to an
> acceptable resolution?

For the extra couple of bucks, literaly, why bother?

The usual retail parts places have 12 bit DACs for ~$6.00

They also have 4 output serial input type for ~13.00.
Driving 4 Axis for that kind of money is cleap IMHO, Granted,
you will be spending 10 times that by the time you are done,
but still cheap.

I would presume the 13th bit is for polarity, and would be
applied to the driver circuit outside the DAC IC itself.

These are one-off prices BTW.

Marc