I have been working with integrated design. Now I am working on a discrete circuit design project. I want to understand how the bias at the input will change the operating point at the output of an op-amp.
Is there any way to calculate it? Since in integrated circuit design we have operating point decided by bias current, but in discrete design I am unable to find the bias current. How will the output operating be set up?
I am yet to design an op-amp on a breadboard, but trying to simulate in Cadence, so wondering how to keep the operating point at output.
I am updating my question here:
I am going to use single supply as +5 V. I will obtain input for the instrumentation amplifier from a transducer whose output might swing differentially between 20-120 mV, over common mode of +2.5 V (VDD/2).
As seen in above image, if I consider R5 to be twice of RG, what will be the output common mode of the two opamps connected as non inverting amplifier (in black colour). Even though I am calculating the differential gain which is obtained to be 5, which means my output common mode voltage most likely to be saturated? I am asking this because the next differential amplifier stage needs to provide some more differential gain.
The calculation of gain is not ideal but approximate derivation.