Difference between OTA and Opamp

[calculus_cuthbert]

Could someone please explain the difference between an OTA and an Opamp???

Is an opamp made of an OTA and a buffer stage?

 

[wpchan05]

Could someone please explain the difference between an OTA and an Opamp???

Is an opamp made of an OTA and a buffer stage?

yes

 

[fcfusion]

OTA is basically an Opamp with high output impedance, meaning no output buffer.

Advantages: Generally greater bandwidth than opamps.

Disadvantages: Cannot use low impedance loads. Generally OTAs are used only for capacitive loads, since DC current is zero.

A MOSFET's gate for example is a capacitive load, so you can use OTAS if you're gonna connect it to MOSFET's.


Opamps are more generic, they're good for most applications that do not require large bandwidths.

 

[hsharghi]

An Opamp generally consist of an output stage (i.e.- Class AB) that is intended to drive a resistive load. [ADC Drivers, Audio Amplifiers, etc.] OTA's are used in switched capacitor circuits where the load is mainly capacitive. An example of this is a folded cascode or 2 stage topology with very high output impedance.