Help in HM9270D or CM8879 DTMF Receiver

[ELEX]

Hi All

i have a controlling project by DTMF (Dual Tone Multi Frequencies) in many Devices

I am using Ic > HM9270D or CM8870 To decoding the tone from the telephone

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when I press number 1 in phone = the output in Ic Q1 = 5v (high) ok

Q1 = 1
Q2 = 0
Q3 = 0
Q4 = 0

The problem it steel in this voltage it's Never back logic 0v (low)

Q1 = 0
Q2 = 0
Q3 = 0
Q4 = 0

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