Opamp

[Vidya Gopal]

why opamp saturate at supply votages?

 

[MikeMl]

How can the output of an opamp rise above Vdd, or go below Vss? It is just an electronic circuit; not a generator.

 

[DerStrom8]

An op-amp is just a bunch of transistors. You can't get a voltage out that's higher than the voltage you apply to the source pins (Vcc and Vee, or Vdd and Vss).

 

[zahwi]

why opamp saturate at supply votages?

Because it has an infinite gain and even when the input is near zero the output is infinite voltage or saturated at supply voltage.

 

[kubeek]

Because it has an infinite gain and even when the input is near zero the output is infinite voltage or saturated at supply voltage.

In theory and without feedback yes, opamps have infinite gain. In practice they have open loop gain of at least a few thousand, but the output voltage is dictated by the feedback and the output is either clamped to the supply rail, or is what it needs to be in order to have negative and positive inputs at the same voltage.

 

[kubeek]

disagree

Care to elaborate on why you disagree with what I said?