What happens if you force a different voltages into opamp?

[asd1249jf]

The professors have taught you that in an opamp, the voltage in one terminal is equal to another.

Suppose you put a 5V voltage source in one terminal and 2V voltage source in the other. What happens then?

 

[dlgoff]

Operational amplifiers are differential. i.e. they are based on the voltage difference of the inputs.

Check out these collection of circuits to see how the inputs are used.

 

[rbj]

The professors have taught you that in an opamp, the voltage in one terminal is equal to another.

only if there is negative feedback (correctly wired up from V_OUT to the V_- terminal usually through some resistance).

Suppose you put a 5V voltage source in one terminal and 2V voltage source in the other. What happens then?

the op-amp output is saturated (hits the rail) at either +V_CC or -V_CC (depending on which of the V₊ or V_- inputs gets connected to the more positive voltage).