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Narrow band pass filter
Sep 06, 2018

A narrow band - pass filter using multiple feedback tracing. The filter USES only one operational amplifier. Compared to all the filters discussed so far, there are some unique features given below this filter.

1. It has two feedback paths, which is why it is called a multi-feedback filter.

2. The operational amplifier is used in inverting mode.

The frequency response of a narrow bandpass filter

In general, narrow band - pass filters are central frequency f c and Q or f c and BW for specific values. Circuit elements are determined from the following relationships. To simplify the design calculation for each C 1 and C 2, you can take the equal C.

R = 1 Q / 2 Π C CA f

R = 2 Π Q/C 2 C (2, 2 Q a F)

3 = Q and R/Π C?

An F is the gain at the center frequency and gives an F = R 3/2r 1 gain however, an F and an F < 2 Q 2 must satisfy the condition.

The center frequency F C of the multi-feedback filter can change a new frequency F C "without changing, gain or bandwidth. This is simply by changing R 2 R "2, so 2 = R 2 [C/F" C]


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