keremcant
Member level 5
hi,
I am assigned to make an two stage op-amp (or OTA) design and I have a specified input common mode range, i.e from 1V to 2.8 Volts.
now, by definition if the transistors(mosfets) are in saturation when I apply those inputs, i.e 2.8 volts and 1 volt, then the circuit meets the specification.
and when I apply those biases and when I check I get all transistors in saturation. so the circut meets the specification. but when I look at the gain of the circuit, the gain decreases by half or more, which means that the circuit is no more in the linear region when I apply those biases, thus I conclude that the specification is not met.
so which one is true? or does the decrease in gain not imply non-linear region of operation?
what is the true way to check if the circuit meets the icmr specification.
thanks in advance
I am assigned to make an two stage op-amp (or OTA) design and I have a specified input common mode range, i.e from 1V to 2.8 Volts.
now, by definition if the transistors(mosfets) are in saturation when I apply those inputs, i.e 2.8 volts and 1 volt, then the circuit meets the specification.
and when I apply those biases and when I check I get all transistors in saturation. so the circut meets the specification. but when I look at the gain of the circuit, the gain decreases by half or more, which means that the circuit is no more in the linear region when I apply those biases, thus I conclude that the specification is not met.
so which one is true? or does the decrease in gain not imply non-linear region of operation?
what is the true way to check if the circuit meets the icmr specification.
thanks in advance
