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From: Mike Warren on 4 Nov 2009 05:25
The LM358 datasheet doesn't specify EIN or S/N. I assume that's
because it's not very good, but using one would simplify my
circuit greatly as I only have +5V available without a lot
of extra work. I need to buffer an audio signal and add a gain
of 2. The input is about 1VRMS.

THD is not super important, but I wouldn't like to add a lot
of noise.

Has anyone used a LM358 in a similar situation successfully?

--
- Mike
From: Phil Allison on 4 Nov 2009 07:05

"Mike Warren"
>
> The LM358 datasheet doesn't specify EIN or S/N. I assume that's
> because it's not very good, but using one would simplify my
> circuit greatly as I only have +5V available without a lot
> of extra work. I need to buffer an audio signal and add a gain
> of 2. The input is about 1VRMS.
>
> THD is not super important, but I wouldn't like to add a lot
> of noise.
>
> Has anyone used a LM358 in a similar situation successfully?


** For non critical applications, within the audio band and with a gain of
only 2 - there is no problem.

However - 2 times 1 volt rms is MORE than 5 volts peak to peak !!

Beware: If the output of the LM358 is cap coupled to the next stage, then
a load resistor to ground is essential to eliminate severe x-over
distortion.

See the Nat Semi 1994 data sheet - page 6.




...... Phil


From: Mike Warren on 4 Nov 2009 07:15
Phil Allison wrote:

>
>"Mike Warren"
>>
>>Has anyone used a LM358 in a similar situation successfully?
>
>
>** For non critical applications, within the audio band and with a gain of
>only 2 - there is no problem.
>
>However - 2 times 1 volt rms is MORE than 5 volts peak to peak !!
>
>Beware: If the output of the LM358 is cap coupled to the next stage,
>then a load resistor to ground is essential to eliminate severe x-over
>distortion.
>
>See the Nat Semi 1994 data sheet - page 6.


Thanks, Phil. That's enough for me to build a test circuit.

--
- Mike
From: TTman on 4 Nov 2009 07:29

"Mike Warren" <miwa-not-this-bit(a)or-this-csas.net.au> wrote in message
news:xn0gh9eln6mnc7000(a)news.aioe.org...
> The LM358 datasheet doesn't specify EIN or S/N. I assume that's
> because it's not very good, but using one would simplify my
> circuit greatly as I only have +5V available without a lot
> of extra work. I need to buffer an audio signal and add a gain
> of 2. The input is about 1VRMS.
>
> THD is not super important, but I wouldn't like to add a lot
> of noise.
>
> Has anyone used a LM358 in a similar situation successfully?
>
> --
> - Mike

TDA7052/a works....


From: Jamie on 4 Nov 2009 19:36
Mike Warren wrote:
> The LM358 datasheet doesn't specify EIN or S/N. I assume that's
> because it's not very good, but using one would simplify my
> circuit greatly as I only have +5V available without a lot
> of extra work. I need to buffer an audio signal and add a gain
> of 2. The input is about 1VRMS.
>
> THD is not super important, but I wouldn't like to add a lot
> of noise.
>
> Has anyone used a LM358 in a similar situation successfully?
>

It looks like it will do what you need.

Have you thought about using a LMV358 ?
THat operates at 2.7..5.5 volts.

THe LPV358 is also lower in current but does
introduce more noise. Which seems to be a big
jump compared to the first 2.

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