samiran_dam
Full Member level 2

Dear All,
Suppose an OTA is driving a capacitive load (CL=5 pF). Now in the behavioral model of the OTA, I have considered an internal high frequency pole [Iout(s)/Vin(s)], non-zero output conductance (Gout). Now when I plot Gm(s) [i.e. Iout(s)/Vin(s)] of the trans-conductor, due to high output impedance and 5 pF load cap, the transfer function is having a low frequency pole as well as the high-frequency one defined internally.
It means for low-frequencies [lower than the first pole frequency (Gout/CL)], transconductance of the trans-conductor does not remain Gm which it is supposed to deliver.
Is this fine? I mean is the model of OTA reasonable enough to try this in different OTA-based circuit?
Please help me.
regards
Sam
Suppose an OTA is driving a capacitive load (CL=5 pF). Now in the behavioral model of the OTA, I have considered an internal high frequency pole [Iout(s)/Vin(s)], non-zero output conductance (Gout). Now when I plot Gm(s) [i.e. Iout(s)/Vin(s)] of the trans-conductor, due to high output impedance and 5 pF load cap, the transfer function is having a low frequency pole as well as the high-frequency one defined internally.
It means for low-frequencies [lower than the first pole frequency (Gout/CL)], transconductance of the trans-conductor does not remain Gm which it is supposed to deliver.
Is this fine? I mean is the model of OTA reasonable enough to try this in different OTA-based circuit?
Please help me.
regards
Sam
Last edited: