-3dB Bandwidth check for active cmos RC filter

[sudeep_]

Can anyone tell me, which can be used for -3dB bandwidth check for active cmos filter using opamp like loop gain vs closed loop gain.

 

[LvW]

I am not sure if I fully understand your question regarding "loop gain vs closed loop gain".
Are you speaking of a 2nd order active lowpass ?

 

[sudeep_]

The circuit is designed as 2nd order Multiple feedback active cmos filter, I am not sure to check -3dB BW by considering Loop gain or Closed loop gain plot.

 

[LvW]

I am not sure to check -3dB BW by considering Loop gain or Closed loop gain plot.

The filter circuit is realized using feedback. Hence, I see no reason to measure/calculate/simulate the 3dB BW not in this closed-loop configuration.

 

[sudeep_]

Could you elobarate this statement. "Hence, I see no reason to measure/calculate/simulate the 3dB BW not in this closed-loop configuration".

 

[LvW]

Could you elobarate this statement. "Hence, I see no reason to measure/calculate/simulate the 3dB BW not in this closed-loop configuration".

At first, can YOU elaborate the term"check"? Does it mean calculation, simulation or measurement?

 

[sudeep_]

-3dB BW measurement for LPF. Which one is used for -3dB BW ( CL or loopgain plot)?

At first, can YOU elaborate the term"check"? Does it mean calculation, simulation or measurement?

 

[LvW]

-3dB BW measurement for LPF. Which one is used for -3dB BW ( CL or loopgain plot)?

As I have mentioned already, the filtering action is caused by a feedback effect - hence, you measure the closed-loop response.

 

[schmitt trigger]

The filter's response, regardless of type, can be obtained three ways:
1) By mathematical analysis
2) By simulation using a sweep
3) By actual hardware testing using a sinewave oscillator and a scope

Is that what you are asking? Because your question is not clear.