MT88L70AN1 Zarlink, MT88L70AN1 Datasheet - Page 12

• Manufacturer Part Number: MT88L70AN1
• Description: DTMF RX 3.58MHz CMOS 3V 20-Pin SSOP Tube
• Manufacturer: Zarlink

Specifications of MT88L70AN1

• Package: 20SSOP
• Operating Frequency: 3.58 MHz
• Typical Supply Current: 2 mA
• Typical Operating Supply Voltage: 3 V
• Minimum Operating Supply Voltage: 2.7 V
• Maximum Operating Supply Voltage: 3.6 V

EXPLANATION OF EVENTS
A)
B)
C)
D)
E)
F)
G)
EXPLANATION OF SYMBOLS
V
ESt
St/GT
Q
StD
TOE
t
t
t
t
t
t
t
t
REC
REC
ID
DO
DP
DA
GTP
GTA
V
ESt
St/GT
Q
StD
TOE
in
1
in
EVENTS
1
-Q
-Q
4
4
TONE BURSTS DETECTED, TONE DURATION INVALID, OUTPUTS NOT UPDATED.
TONE #n DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN OUTPUTS.
END OF TONE #n DETECTED, TONE ABSENT DURATION VALID, OUTPUTS REMAIN LATCHED UNTIL NEXT VALID
OUTPUTS SWITCHED TO HIGH IMPEDANCE STATE.
TONE #n+1 DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN OUTPUTS (CURRENTLY
ACCEPTABLE DROPOUT OF TONE #n+1, TONE ABSENT DURATION INVALID, OUTPUTS REMAIN LATCHED.
END OF TONE #n+1 DETECTED, TONE ABSENT DURATION VALID, OUTPUTS REMAIN LATCHED UNTIL NEXT
DTMF COMPOSITE INPUT SIGNAL.
EARLY STEERING OUTPUT. INDICATES DETECTION OF VALID TONE FREQUENCIES.
STEERING INPUT/GUARD TIME OUTPUT. DRIVES EXTERNAL RC TIMING CIRCUIT.
4-BIT DECODED TONE OUTPUT.
DELAYED STEERING OUTPUT. INDICATES THAT VALID FREQUENCIES HAVE BEEN PRESENT/ABSENT FOR THE
TONE OUTPUT ENABLE (INPUT). A LOW LEVEL SHIFTS Q
MAXIMUM DTMF SIGNAL DURATION NOT DETECTED AS VALID.
MINIMUM DTMF SIGNAL DURATION REQUIRED FOR VALID RECOGNITION.
MINIMUM TIME BETWEEN VALID DTMF SIGNALS.
MAXIMUM ALLOWABLE DROP OUT DURING VALID DTMF SIGNAL.
TIME TO DETECT THE PRESENCE OF VALID DTMF SIGNALS.
TIME TO DETECT THE ABSENCE OF VALID DTMF SIGNALS.
GUARD TIME, TONE PRESENT.
GUARD TIME, TONE ABSENT.
TONE.
HIGH IMPEDANCE).
VALID TONE.
REQUIRED GUARD TIME THUS CONSTITUTING A VALID SIGNAL.
t
REC
A
DECODED TONE # (n-1)
t
DP
t
GTP
t
PSrD
t
Figure 7 - Timing Diagram
PQ
t
Zarlink Semiconductor Inc.
REC
TONE #n
B
MT88L70
12
t
QStD
C
# n
1
t
ID
-Q
t
DA
4
TO ITS HIGH IMPEDANCE STATE.
t
GTA
TONE
#n + 1
E
HIGH IMPEDANCE
t
PTD
t
DO
D
F
TONE
#n + 1
# (n + 1)
t
PTE
G
Data Sheet
V
TSt