OTAs FTW - some application notes for us earthlings

Started by Hatredman, November 17, 2014, 07:21:03 PM

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Hatredman

Don't know if this is the right place, but just broke a toe stumbling on it and methinks it's gonna interest some blokes.

Applications of the CA3080 High-Performance
Operational Transconductance Amplifiers (Intersil)
http://users.ece.gatech.edu/~lanterma/sdiy/datasheets/ota/ca3080apnote.pdf

UNDERSTANDING AND USING 'OTA' OP-AMP ICs
(awesomely didatic, turn OTAs into VCAs, VCFs, VCOs, Ring Modulators etc)
http://www.idea2ic.com/LM13600/UsingOTAs2.pdf

Applications of an OTA Current Controlled Amplifier
(I liked the fadeover morpher stuff)
http://www.geofex.com/Article_Folders/VCA%20Applications.pdf

OTA Application Circuits
(See the Variable Peak Clipper)
http://www.musicsynthesizer.com/diy/grant/OTA.html

Demystifying the Operational Transconductance Amplifier (Texas Instruments)
(Brings some new OTAs as "ideal transistors" [or transvestites])
http://www.ti.com/lit/an/sboa117a/sboa117a.pdf
Kirk Hammet invented the Burst Box.

bluebunny

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Ohm's Law - much like Coles Law, but with less cabbage...

PRR

> Demystifying the Operational Transconductance Amplifier (Texas Instruments)

This is actually a VERY different part than the 3080 OTA.

In that paper, page 2 Fig 1: the '3080 is top-right, "Voltage Controlled Current Source" (except you really need to work the '3080 current-controlled), the part the paper is talking about is top-center, "Transconductor". I never seen the Diamond or CC II+ called "OTA", though the CC II+ has some relation.

I think this new device would sell a lot better if those papers and datasheets were re-written by someone who didn't know the product so well. Basics are skipped and implementation idiosyncrasies are rushed.
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Hatredman

Quote from: PRR on November 20, 2014, 12:39:53 AM
> Demystifying the Operational Transconductance Amplifier (Texas Instruments)
This is actually a VERY different part than the 3080 OTA.

Yes, it is.

But I thought it would be interesting anyway. Nover saw a pedal built around one of those.
Kirk Hammet invented the Burst Box.

tubegeek

"The first four times, we figured it was an isolated incident." - Angry Pete

"(Chassis is not a magic garbage dump.)" - PRR