michael brown wrote:
> The output pin idles at 2.5V as I'd expect, but
> when the output reaches about 2.5V p-p, it starts clipping on the bottom
> first, quickly followed by clipping at the top.  I checked everything
> with the scope, and the output is centered on the 2.5V dc bias (pin 6).
> I know that many op-amps can't go rail to rail, but surely shouldn't I
> be able to get closer to the rails than about 1.25V?

Surely you should be able to read this information directly from the data
sheet.  RTFM!  Just about every opamp data sheet I've seen has a spec for
"output voltage swing" or something similar.

> I just noticed that I didn't include the 22k resistor to ground on the
> output of the 741.  What is it's purpose?

I don't see an obvious one.  Of course just because a circuit is published
on the internet doesn't mean it's a good design.

> BTW, I found
> it interesting that the circuit doesn't produce anything out unless you
> have some kind of negative feedback resistor.  I expected the op-amp to
> run at max gain without the negative feedback.

It does, but that resistor also provides a DC feedback path.


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