dramrattan
Member
Hi,
I implemented this circuit and it works fine but now that i have to demonstrate it soon i don't know why each part was choosen as the values seen in the circuit.
From reading the MT8870 DTMF decoder datasheet i know its the differential input configuration used and that gain setting can be used...Why does it need a gain and how dto calculate these values shown?
I implemented this circuit and it works fine but now that i have to demonstrate it soon i don't know why each part was choosen as the values seen in the circuit.
From reading the MT8870 DTMF decoder datasheet i know its the differential input configuration used and that gain setting can be used...Why does it need a gain and how dto calculate these values shown?