[sdiy] ad844 current feedback amplifier??

[Harry Bissell]

The best description I can think of for the LM3900 is "Current Controlled Voltage Source"

Ask Bob Pease what he thinks of the LM3900 (and stand way back :^)

H^) harry


----- Original Message -----
From: John Speth <John.Speth at coherent.com>
To: lanterma at ece.gatech.edu, synth-diy at dropmix.xs4all.nl
Sent: Mon, 13 Dec 2010 14:35:34 -0500 (EST)
Subject: Re: [sdiy] ad844 current feedback amplifier??

> > In short the current-feedback op-amp has little to offer the
> audio market,
>
> That's my impression too.
>
> I recall that Serge used the LM3900 a lot, and am curious about
> what his thinking was on that.
>
> The other main place I recall it showing up is in a four-pole ARP
> filter; see Don Tillman's awesome synth patent page:
>
> http://www.till.com/articles/arp/patents.html#US04011466

Historical tidbit: The PAIA modules designed in the 70s used the LM3900 in many designs.  IIRC, the LM3900s were used in the VCA, VCO, VCF, and sequencer.  In the sequencer, I think LM3900s were used as shift registers.  You could tell it was the designers' (John Simonton, perhaps) favored part.  See http://paia.com/manuals/

While following this thread I was wondering if a "current feedback amplifier" is another name for a "Norton amplifier" which is the LM3900's moniker.  Does anyone know if they're the same?

National Semi has a very old and quite extensive app note for the LM3900.  See http://www.national.com/an/AN/AN-72.pdf.

JJS


The information contained in this communication is confidential and may be legally privileged. It is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. If you are not the intended recipient you are hereby (a) notified that any disclosure, copying, distribution or taking any action with respect to the content of this information is strictly prohibited and may be unlawful, and (b) kindly requested to inform the sender immediately and delete any copies. Coherent is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva