Operational Amplifier / Op-Amp Band Pass Filter

- basic operational amplifier / op-amp active band pass filter circuit with details of how to determine the values for the frequencies required.

A variety of operational amplifier, op-amp circuits including:
[1] Operational amplifier basics
[2] Op-amp circuit gain summary
[3] Inverting op-amp
[4] Inverting op-amp
[5] Op-amp high pass filter
[6] Op-amp low pass filter
[7] Op-amp bandpass filter
[8] Op-amp variable gain amplifier
[9] Op-amp notch filter circuits
[9] Operational amplifier multivibrator
[11] Op-amp bistable
[12] Op-amp comparator
[13] Op-amp Schmitt trigger

The design of band pass filters can become very involved even when using operational amplifiers. However it is possible to simplify the design equations while still being able to retain an acceptable level of performance of the operational amplifier filter for many applications.

As only one operational amplifier is used in the filter circuit, the gain should be limited to five or less, and the Q to less than ten. In order to improve the shape factor of the operational amplifier filter one or more stages can be cascaded. A final point to note is that high stability and tolerance components should be used for both the resistors and the capacitors. In this way the performance of the operational amplifier filter will be obtained.