MT3170B/71B, MT3270B/71B, MT3370B/71B
t
REC
DTMF
Tone #n
DTMF
Tone #n + 1
t
DO
DTMF
Tone
#n + 1
INPUT
Input
Signal
t
DP
t
DA
ESt
(MT3x70B)
t
REC
DStD
(MT3x71B)
t
ID
ACK
LSB
SD
MSB
LSB
MSB
t
SA
t
SD
Input
Signal
Envelope
b
0
b
1
b
2
b
3
b
0
b
1
b
2
b
3
t
DO
-
t
ID
-
t
REC
-
t
REC
-
t
DA
-
t
DP
-
t
SA
-
t
SD
-
maximum allowable dropout during valid DTMF signals. (MT3x7xB).
minimum time between valid DTMF signals (MT3x71B).
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).
supervisory tone integrator decay time (MT3x7xB).
Figure 4 - Timing Diagram
ESt/DStD
1/
f
ACK
V
IH
ACK
V
IL
t
PAD
V
IH
V
IL
t
DH
b
0
LSB
b
1
b
2
b
3
MSB
DTMF Energy
Detect
SD
DTMF Energy
Detect
Figure 5 - ACK to SD Timing
4-10
MITEL [ MITEL NETWORKS CORPORATION ]
