MT3170B/71B, MT3270B/71B, MT3370B/71B
Data Sheet
tDO
tREC
DTMF
DTMF
Tone #n
DTMF
Input
Signal
Tone
INPUT
Tone #n + 1
#n + 1
tDA
tDP
ESt
(MT3x70B)
tID
tREC
DStD
(MT3x71B)
ACK
SD
tSA
tSD
LSB
LSB
MSB
MSB
Input
Signal
Envelope
b0b1b2b3
b0b1b2b3
tDO
tID
- maximum allowable dropout during valid DTMF signals. (MT3x7xB).
- minimum time between valid DTMF signals (MT3x71B).
tREC
tREC
tDA
tDP
- maximum DTMF signal duration not detected as valid (MT3x7xB).
- minimum DTMF signal duration required for valid recognition (MT3x71B).
- time to detect the absence of valid DTMF signals (MT3x70B).
- time to detect the presence of valid DTMF signals (MT3x70B).
- supervisory tone integrator attack time (MT3x7xB).
tSA
tSD
- supervisory tone integrator decay time (MT3x7xB).
Figure 4 - Timing Diagram
ESt/DStD
1/fACK
VIH
ACK
VIL
tPAD
tDH
VIH
DTMF Energy
Detect
DTMF Energy
Detect
SD
b0
LSB
b1
b2
b3
MSB
VIL
Figure 5 - ACK to SD Timing
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Zarlink Semiconductor Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
