Mr RB
Well-Known Member
Hi, I have a simple application which needs a crude bandpass filter, to pass signals between 5kHz to 10kHz.
The bad news is that I can't use opamps as PCB space is at a premium, and wanted to do it with minimal parts (preferably just discretes or maybe 1 transistor etc) for cost issues too.
The good news is that the incoming signal is quite large, probably 5v peak to peak, and I only need about 200mV peak to peak output (into a high impedance audio input) so there is plenty of headroom for a passive filter.
It doesn't need to be that sophisticated, just to remove most of the guff below 5kHz and above 10kHz.
Options I am considering are overlapping lowpass and highpass passive filters, or maybe a low-Q LC filter centred on 7.5kHz.
I appreciate any suggestions.![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
The bad news is that I can't use opamps as PCB space is at a premium, and wanted to do it with minimal parts (preferably just discretes or maybe 1 transistor etc) for cost issues too.
The good news is that the incoming signal is quite large, probably 5v peak to peak, and I only need about 200mV peak to peak output (into a high impedance audio input) so there is plenty of headroom for a passive filter.
It doesn't need to be that sophisticated, just to remove most of the guff below 5kHz and above 10kHz.
Options I am considering are overlapping lowpass and highpass passive filters, or maybe a low-Q LC filter centred on 7.5kHz.
I appreciate any suggestions.