op amp circuit

I think you should think in terms of a dual opamp and a 10X high pass filter (2 or 3 poles) followed by a 10X low pass filter (2 or 3 poles).

You might download a free copy of this little filter design aid to play around with variations.

This circuit will do what you want,but requires a big capacitor on the input. If you use a dual opamp like the NE5532 you need the same space but can reduce the cap by a factor of 100 or more. The noise will go up tho.

|| .----||--. | 3n3|| | \\] ___ | ___ | o---|]--|___|--o--|___|-o /]+ 11k | 1M1 | 150u | |\\ | '--|-\\ | | >--o---o .--|+/ | |/ NE5534 ___ | ___ GND-|___|-o-|___|-VCC 22k | 22k --- ---0u47 | === GND

This circuit will do what you want,but requires a big capacitor on the input. If you use a dual opamp like the NE5532 you need the same space but can reduce the cap by a factor of 100 or more. The noise will go up tho.

|| .----||--. | 3n3|| | \\] ___ | ___ | o---|]--|___|--o--|___|-o /]+ 11k | 1M1 | 150u | |\\ | '--|-\\ | | >--o---o .--|+/ | |/ NE5534 ___ | ___ GND-|___|-o-|___|-VCC 22k | 22k --- ---0u47 | === GND

A frequency range of 450:1 is way too large for a simple bandpass filter. You should have separate low-pass and high-pass stages for this.

Best regards,

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

that page doesnt give the single op amp sallen key bandpass filter, wich u might look at as an alternative, the one shown is a multiple feedback type.

try this calculator ....

Colin =^.^=