Topic: Analog Circuits
A second-order band-pass active filter can be obtained by cascading a low pass second order section having cut off frequency $f_{OH}$ with a high pass second order section having cut-off frequency $f_{OL}$ provided
- A. $f_{OH}>f_{OL}$
- B. $f_{OH}<f_{OL}$
- C. $f_{OH}=f_{OL}$
- D. $f_{OH}\le\frac{1}{2}f_{OL}$
Answer: A. $f_{OH}>f_{OL}$
Explanation: To form a pass band, the higher cut-off frequency (from the low-pass filter, $f_{OH}$) must be greater than the lower cut-off frequency (from the high-pass filter, $f_{OL}$).