steviemidnight
Junior Member level 1
i have an elektret microphone that only produces tiny voltages with a max impedence of 1.5k. i need to filter this with a bandpass filter. then amplify this so i can input it into my adcPIC or CVSD. i am also having problems with my ISIS simulation of the mic- ie i can`t get it to work.
Ineed some good proteus librarys any suggestions i have tried there website
Band pass filters 200-3000Hz:
bessel - no phase problems but poor cut off
chebychev - phase problems and good drop off
butterworth - somewhere in between the above.
should i go for an active or passive filter i need some help in the differnece please. As i need to amplify the mic output it might as well be a active filter - any op-amp suggestions please. i would like to keep this compact but have done little work with op-amps, im looking at some kind of samm-key solution. Am i on the right lines please and any suggestions
i have tested the Tx and Rx which work fine and go up to 150KHz before loss of signal with a constant square wave. i will buy the CVSD chips but i am still going to try and encode a adcPIC and decode into a UART then DAC at the Rx end. - have not got much further here
Ineed some good proteus librarys any suggestions i have tried there website
Band pass filters 200-3000Hz:
bessel - no phase problems but poor cut off
chebychev - phase problems and good drop off
butterworth - somewhere in between the above.
should i go for an active or passive filter i need some help in the differnece please. As i need to amplify the mic output it might as well be a active filter - any op-amp suggestions please. i would like to keep this compact but have done little work with op-amps, im looking at some kind of samm-key solution. Am i on the right lines please and any suggestions
i have tested the Tx and Rx which work fine and go up to 150KHz before loss of signal with a constant square wave. i will buy the CVSD chips but i am still going to try and encode a adcPIC and decode into a UART then DAC at the Rx end. - have not got much further here