ashrafsazid
Advanced Member level 4
Hi,
I have designed a gain boosted OTA for SC amplifier operation applied it to a test bench of gain setting of 1. Where Cf=Ci, hence Closed Loop gain 1.
With such a configuration in the testbench. If I swing input DC from -vdd to +vdd, the output will sweep from -vdd to +vdd, as the CL gain is 1. Now, the OTA gain curve (Vout vs. Gain) for the desired Vout range can be checked by that Vin range from the parametric sweep of Vin.
I included here my gain curve
The yellow curve is for vdd= 1.6V, where for Vin=1.2 (that means Vout= 1.2) the gain is around 75 dB, which is desired.
But if I see the transient behavior, For a diff input of 1 - I get 0.9987, this is okay. But, for diff input of 1.2, I do not get 1.2 rather 1.14 only. from the curve, it is clear that there is no settling time issue, But confused why it is not settling to final 1.2 volt. Can you please explain what could be the reason?
Please help me!
Thanks in advance.
I have designed a gain boosted OTA for SC amplifier operation applied it to a test bench of gain setting of 1. Where Cf=Ci, hence Closed Loop gain 1.
With such a configuration in the testbench. If I swing input DC from -vdd to +vdd, the output will sweep from -vdd to +vdd, as the CL gain is 1. Now, the OTA gain curve (Vout vs. Gain) for the desired Vout range can be checked by that Vin range from the parametric sweep of Vin.
I included here my gain curve
The yellow curve is for vdd= 1.6V, where for Vin=1.2 (that means Vout= 1.2) the gain is around 75 dB, which is desired.
But if I see the transient behavior, For a diff input of 1 - I get 0.9987, this is okay. But, for diff input of 1.2, I do not get 1.2 rather 1.14 only. from the curve, it is clear that there is no settling time issue, But confused why it is not settling to final 1.2 volt. Can you please explain what could be the reason?
Please help me!
Thanks in advance.