dtmf testing

Thread Starter

miso

Joined Aug 25, 2010
2
i have been trying to test the dtmf mt8880 ic just to check the output frequency and check how its working i have followed the connection shown in the data sheet but apparently i have failed to get the desired frequencies for the keypads :( any suggestion ???!!!


thanks alot in advance
 

Thread Starter

miso

Joined Aug 25, 2010
2
thanks for the concern ,,
actually i fed up trying with it:( the circuit i used for testing is attached i have used the connection in fig 13 for testing and i failed to get an output frequency from it any idea if the dtmf ht9200b is easier to deal with ?
 

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