Jim cage
Full Member level 2
Hi everybody,
Here is a question for you. suppose you Have an amplifier with common source configuration with ideal current source load.
The gain of this amplifier is therefore the intrinsic gain = gm*ro.
(assume this is a device with short channel lenght e.g., 0.18um).
Since the output resistance ,ro, is a function of Vds of the transistor (Channel length modulation, DIBL, hot electrons)...then the intrinsic gain is a function of Vds!
i.e., gain=gm*ro=f(Vds)
Assuming that you want gain of 20[V/V] this means that the output swing needs to be confined from one min voltage to output voltage.
The question: If the gain is changing with respect to the output swing, doesnt it means that the amplifier is "very very non-linear"?
(assuming very small input signal which dont excite the non-linearity due to the input).
Attached file is a figure from EE240 taught last year.
Regards,
Here is a question for you. suppose you Have an amplifier with common source configuration with ideal current source load.
The gain of this amplifier is therefore the intrinsic gain = gm*ro.
(assume this is a device with short channel lenght e.g., 0.18um).
Since the output resistance ,ro, is a function of Vds of the transistor (Channel length modulation, DIBL, hot electrons)...then the intrinsic gain is a function of Vds!
i.e., gain=gm*ro=f(Vds)
Assuming that you want gain of 20[V/V] this means that the output swing needs to be confined from one min voltage to output voltage.
The question: If the gain is changing with respect to the output swing, doesnt it means that the amplifier is "very very non-linear"?
(assuming very small input signal which dont excite the non-linearity due to the input).
Attached file is a figure from EE240 taught last year.
Regards,