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CMOS Current Operational Amplifiers

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Eknath

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I want to implement a Current operational Amplifier(COA), I have difficulty in finding the applications where COA are used. I want some references that can explain the applications of COA in detail and not just in one line.
 

erikl

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I think it's the same as an Operational Transconductance Amplifier (OTA), e.g. CA3080 (from TI, Intersil): relatively low input impedance and high output impedance, both (together) programmable. Search for their dataSheets and application notes!
 

LvW

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erikl

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I think the OTA is a controlled current source with a high input resistance (with other words: A voltage-to-current converter).
I think the CA3080 isn't far away from being called a COA, too: its input resistance is relatively low compared to that of an OpAmp: see p.2 of its dataSheet:

Anyway, thanks for the COA paper link!
 

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FvM

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I don't see CA3080 related to current mode amplifiers. It's a basic bipolar OTA, exposing a differential pair with respective low input resistance. Implementing a basic OTA in CMOS gives similar behaviour with high input resistance.
 
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    LvW

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