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Chip Amps Amplifiers based on integrated circuits

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Old 22nd September 2004, 01:10 PM   #71
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Quote:
Originally posted by janneman
Yes that makes sense, what can these regs give, 5 amps or so?
Well... sort of.
From the datasheet:

"The LM138 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 5A over a 1.2V to 32V output range.
The current limit circuitry allows peak currents of up to 12A to be drawn from the regulator for short periods of time. This allows the LM138 to be used with heavy transient loads and speeds start-up under full-load conditions."

Seams quite good for a class AB amp that plays music.
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Old 22nd September 2004, 08:26 PM   #72
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hmm, seems pretty good, parellel them and you could drive a pretty large amp with them.

Is there a negative version?
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Old 22nd September 2004, 09:05 PM   #73
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Quote:
Originally posted by carlosfm


Well... sort of.
From the datasheet:

"The LM138 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 5A over a 1.2V to 32V output range.
The current limit circuitry allows peak currents of up to 12A to be drawn from the regulator for short periods of time. This allows the LM138 to be used with heavy transient loads and speeds start-up under full-load conditions."

Seams quite good for a class AB amp that plays music.

Indeed. 12 amps peak in 4 ohms with a supply of say 50V dc + and -, that's a healthy 200W++. Not bad for an integrated regulator.
Has anybody tried these regulators with a separate external, high speed etc error opamp?

Jan Didden
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Old 22nd September 2004, 09:59 PM   #74
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Quote:
Originally posted by janneman
Has anybody tried these regulators with a separate external, high speed etc error opamp?
No, but tell us more about that.
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Old 22nd September 2004, 10:51 PM   #75
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Quote:
capable of supplying in excess of 5A over a 1.2V to 32V output range.
I thought 5A is possible only up to 25V....

And then the max current rating drops from 26V...
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Old 23rd September 2004, 12:02 AM   #76
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Quote:
Originally posted by jamesjung21
I thought 5A is possible only up to 25V....
And then the max current rating drops from 26V...
Where did you see that?
It may have escaped me...
What is important is that VIN-VOUT is less than 10V.
Like on this graph, on page 3 of the datasheet:
Attached Images
File Type: png lm338 current.png (6.4 KB, 67 views)
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Old 28th September 2004, 05:10 AM   #77
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Quote:
Originally posted by leafster99
Isn't this the same amp at the bottom of this page?: http://www.hilberink.nl/amps/lm3875schema.htm

Now that is a funny read.

That is funny. Hey Karma. They said your amp looks like spaghetti
MMmmmmmmmmmmm, spaghetti


well sure i was in a hurry new job and all. heh im a few hundred
away from the first piece of a mark levinson system i have had my eye on.

ware is the marble saw you ordered?


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