is there any important point to be considered while interfacing the DTMF chip to the phone line? i 'm currently working on a DTMF decoder proj and got stuck at the interfacing between the telephone line and the DTMF MT8870 and the interfacing between MT8870 and PIC18F452. somebody pls suggest me on this. thanks.
interfacing
Started by ●February 1, 2006
Reply by ●February 1, 20062006-02-01
npp wrote:> is there any important point to be considered while interfacing the > DTMF chip to the phone line? > i 'm currently working on a DTMF decoder proj and got stuck at the > interfacing between the telephone line and the DTMF MT8870 and the > interfacing between MT8870 and PIC18F452. > somebody pls suggest me on this. > thanks.My suggestion is to be more specific about where you are stuck. Cheers! --M
Reply by ●February 1, 20062006-02-01
The most important point to consider would be that, without a line interface circuit, the chip will likely fry. Check out http://assets.zarlink.com/AN/msan_108.pdf for the recommended line interface circuit and some hints regarding the chip-to-pic interface. Hope this helps. BR, Dan