analog_curious
Member level 2
Hi all
I just have a doubt on cascode amplifier. Is it really necessary to use the same dimension device for the cascode stage transistor in a cascode amplifier.
If so, what is the reason and if not what are the benefits by choosing other dimension device.
One more question: If the resistance(Rd) between the supply and the drain end of cascode transistor is a passive resistor and not an active load then I would expect the same AC voltage gain as single stage, provided the same dimension device and same Rd is used in both single stage and in cascode stage.Because the output resistance is still dominated by the output resistance(Rd) in the voltage gain expression(gm*Rout)
Am I right or going wrong somewhere?
Thanks a lot people
Dan
I just have a doubt on cascode amplifier. Is it really necessary to use the same dimension device for the cascode stage transistor in a cascode amplifier.
If so, what is the reason and if not what are the benefits by choosing other dimension device.
One more question: If the resistance(Rd) between the supply and the drain end of cascode transistor is a passive resistor and not an active load then I would expect the same AC voltage gain as single stage, provided the same dimension device and same Rd is used in both single stage and in cascode stage.Because the output resistance is still dominated by the output resistance(Rd) in the voltage gain expression(gm*Rout)
Am I right or going wrong somewhere?
Thanks a lot people
Dan