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Help me, pliz DTMF CM8888 IC to generate DTMF signal

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chank_02

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transformateur ax141

I use DTMF CM8888 IC to generate DTMF signal. I've success to generate it. But, it doesn't transfer to PSTN line. I've check the output signal after trough the transformer, the signal not same with the first it generated. I use AX141 transformer to match the impedance. So, Would you like to help me about to solve it.

Thank's b4 (Ichank)
 

ax141 transformer

Hi

Upload your electronic circuit (schematic) for review

All the best

Bobi
 

Help me, pliz (DTMF)

hi can U connect to phone line without isolation ?
if U can connect it directly by a RC filter to phone line or upload your sch diagram
 

Help me, pliz (DTMF)

OK you need buffer aplifier, something like single end to differential converter, als check 2 to 4 converter with 600 ohm match
 

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