Take a look on LM358 datasheet here:
http://www.datasheetcatalog.com/datasheets_pdf/L/M/3/5/LM358%20MDA.shtml
at the "current monitor" application on page 13.

Vasile

On 10/3/06, Mark Rages <markrages@gmail.com> wrote:
> Forgot the tag
>
> On 10/2/06, Mark Rages <markrages@gmail.com> wrote:
> > Hi,
> >
> > I'm wanting to measure a current with a 12F675.  I want to have a
> > low-side sense resistor and measure it directly with the ADC.  Of
> > course, when building a current sensor, it saves power to use a
> > low-value sense resistor, which makes a small full-scale voltage.  I
> > plan to compensate for this by setting Vref to a low value.  But I'm
> > not seeing anything in the datasheet to tell me how low I can go, or
> > what problems I will see if I go too low.  Noise?  Fixed offset?  Do
> > others have experiences with this?  Am I looking in the wrong place?
> >
> > Regards,
> > Mark
> > markrages@gmail.com
> > --
> > You think that it is a secret, but it never has been one.
> >   - fortune cookie
> >
>
>
> --
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