On Jul 1, 3:07 pm, John Fields <jfie...@[EMAIL PROTECTED]
> wrote:
> On Tue, 1 Jul 2008 13:30:05 -0700 (PDT), mrdarr...@[EMAIL PROTECTED]
wrote:
> >On Jul 1, 12:15 pm, John Fields <jfie...@[EMAIL PROTECTED]
> wrote:
> >> On Tue, 1 Jul 2008 11:55:35 -0700 (PDT), mrdarr...@[EMAIL PROTECTED]
wrote:
> >> >On Jul 1, 11:48 am, Don Bowey <dbo...@[EMAIL PROTECTED]
> wrote:
> >> >> On 7/1/08 11:30 AM, in article
> >> >> a1662fad-e0d7-4306-9e20-195abb1e7...@[EMAIL PROTECTED]
>
> >> >> "mrdarr...@[EMAIL PROTECTED]
" <mrdarr...@[EMAIL PROTECTED]
> wrote:
> >> >> > I was reading the datasheet for the LM1875
> >> >> >http://www.national.com/ds.cgi/LM/LM1875.pdf
>
> >> >> > and I noticed that they do have a schematic for a single supply
(as
> >> >> > opposed to a +/- supply).
>
> >> >> > If running on a single supply, does the chip amplifer consume
> >> >> > significant power during quiet tracks?
>
> >> >> > Would this be pretty much the same as running the amplifier in
Class A
> >> >> > mode (vs. Class AB)?
>
> >> >> > I'm trying to figure out if I really need a +/- power supply, or
if I
> >> >> > can just go with a single supply (easier to build).
>
> >> >> > Thanks,
>
> >> >> > Michael
>
> >> >> The datasheet does have a "Typical Single Supply Operation"
schematic.
> >> >> Have another look.
>
> >> >Yes, that's what I said. There is a schematic. It's on Page 2.
> >> >(amused grin)
>
> >> ---
> >> Look at "Supply Current" on page 2 and read: "Power Dissipation and
> >> Heat Sinking" on page 6.
>
> >> JF
>
> >Ah, so apparently the chip does not use more power with a single
> >supply than with a +/- supply.
>
> >Is there any reason why I should NOT use a single supply with this
> >chip?
>
> ---
> I don't think so, but try it and see if it works the way you want it
> to. If it does you've saved a supply, but if it doesn't it's only
> cost you a handful of discretes.
>
> JF
Good point. Thanks.
Michael
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