CMOS Current Operational Amplifiers

[Eknath]

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]

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]

I think it's the same as an Operational Transconductance Amplifier (OTA),

In contrast - I think the OTA is a controlled current source with a high input resistance (with other words: A voltage-to-current converter).

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See here:
https://link.springer.com/article/10.1023/A:1008384006037?LI=true#page-1

 

[erikl]

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!

 

[FvM]

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.