Biquad Filter OP Amp Design Question?

[sslin_2001]

Currently I am working on designing an OPA with CMOS 0.18um process for Tow-thomas Biquad Active Filter. In order to increase BW, I am thinking of using a simple “single stage CS amplifier (i.e. w/o adding the Class-A or AB output buffer). Is it OK? Will it be any problems?

Is there other better solutions?

 

[Audioguru]

There are plenty of opamps available. Why design a new one?
Oh, a school assignment?

 

[sslin_2001]

power is issue.

 

[LvW]

Currently I am working on designing an OPA with CMOS 0.18um process for Tow-thomas Biquad Active Filter. In order to increase BW, I am thinking of using a simple “single stage CS amplifier (i.e. w/o adding the Class-A or AB output buffer). Is it OK? Will it be any problems?
Is there other better solutions?

The output of an opamp and/or of a filter always should be low-resistive (to be independent on any load). Hence, a simple CS stage is not a good solution.

 

[sslin_2001]

Thanks LvW. You are right. CS is not a good solution even if I have known the parasitic RC and feedback RC of the filter. Its linearity will be a problem since the load will be varied.

Do you have other suggested solutions or infos if my 3dB BW need to >=2.5MHz with an acceptable uA consumption?