Why OPAMP is considered VCVS and OTA considered as VCCS

[KGF KING]

i understand OTAs are basically Opamps without the output stage but how this difference causing OPAMP become VCVS and OTA as VCCS. Can someone explain this in terms of small signal models because i'm confusing the theory that tells connecting Vout at the drain terminal of amplifier because that node considered to be high impedance node (which means any changes in the load doesn't affect your Vgs of the mosfets but then when comes to OPAMP and OTA since both have almost similar structure why OPAMP become low output impedance and OTA become high output impendance. And also why OTA time driving known for capacitive loads and OPAMP is for driving resistive load?

 

[dick_freebird]

Look at the transfer function - V/V for op amp, I/V for OTA. What else makes sense as a basic idealization?

For OTA external C is stabilizing, the primary pole. For op amp already compensated, load C is a second pole and destabilizing.

 

[FvM]

OPAMP and OTA have different output stage. OPAMP has low impedance output buffer, OTA has current source output.

 

[danadakk]

Comparison :

What is the Difference Between Op-Amp and Transconductance Amplifier? Explained - electronicstalk.org

Among various amplifiers, Operational Amplifiers (Op-Amps) and Transconductance Amplifiers are key players in diverse applications like signal processing and control systems. Op-Amps are the go-to for high input impedance and voltage amplification, often using complex feedback systems for...

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