lawfulgm
Junior Member level 1
Hi all,
I am a bit confused about this output impedance measurement. When we measure the output impedance, we short the input to ground and apply AC source to the output.
Supposed I want to measure simple NMOS input amplifier with PMOS load followed by a shunt-feedback amplifier's output impedance, should I ground DC bias of the input transistors to the ground as well? what about output ? when I apply AC voltage to the output, should I apply a proper DC voltage as well? or put an AC coupling capacitor b/w AC source and the output node?
I think what I should do is only short input AC source to the GND but apply proper DC bias voltage to the input, and place an AC coupling capacitor b/w the output node and AC source at the output.
What is the correct way to measure this? what about in transient situation then?
Thanks,
I am a bit confused about this output impedance measurement. When we measure the output impedance, we short the input to ground and apply AC source to the output.
Supposed I want to measure simple NMOS input amplifier with PMOS load followed by a shunt-feedback amplifier's output impedance, should I ground DC bias of the input transistors to the ground as well? what about output ? when I apply AC voltage to the output, should I apply a proper DC voltage as well? or put an AC coupling capacitor b/w AC source and the output node?
I think what I should do is only short input AC source to the GND but apply proper DC bias voltage to the input, and place an AC coupling capacitor b/w the output node and AC source at the output.
What is the correct way to measure this? what about in transient situation then?
Thanks,