-3dB Bandwidth check for active cmos RC filter

Status
Not open for further replies.
S

sudeep_

Member level 1
Joined
Jul 31, 2013
Messages
40
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
261
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.
 

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 ?
 

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.
 

sudeep_ said:
I am not sure to check -3dB BW by considering Loop gain or Closed loop gain plot.
Click to expand...

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.
 

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

sudeep_ said:
Could you elobarate this statement. "Hence, I see no reason to measure/calculate/simulate the 3dB BW not in this closed-loop configuration".
Click to expand...
At first, can YOU elaborate the term"check"? Does it mean calculation, simulation or measurement?
 

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


LvW said:
At first, can YOU elaborate the term"check"? Does it mean calculation, simulation or measurement?
Click to expand...
 

sudeep_ said:
-3dB BW measurement for LPF. Which one is used for -3dB BW ( CL or loopgain plot)?
Click to expand...

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

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.
 
Last edited:

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…