AC ELECTRICAL CHARACTERISTICS
DTMF TRANSMIT CHARACTERISTICS (VCC = 5 V ± 10%, TA = – 20 to 70°C)
Parameter
Symbol
Condition
Min
Typ
Transmit Level
Low Group
Vfl
Attenuator = 0 dB
—
2.5
High Group
Vfh
fosc = 3.579545 MHz
VTxA1 – VTxA2
—
3.5
High Group Pre–Emphasis
PE
RL = 1.2 kΩ
0
—
DTMF Distortion
DIST
—
5
DTMF Frequency Variation
∆fV
–1
—
Out–of–Band Energy
(See Figure 1)
VOE
—
—
Setup Time
tosc
—
4
TRANSMIT ATTENUATOR CHARACTERISTICS (VCC = 5 V ± 10%, TA = – 20 to 70°C)
Parameter
Symbol
Condition
Min
Typ
Attenuator Range
ARNG
0
—
Attenuator Accuracy
AACC
1 dB – 5 dB
– 0.5
—
6 dB – 9 dB
–1
—
10 dB – 15 dB
– 1.7
—
DTMF RECEIVER CHARACTERISTICS (VCC = 5 V ± 10%, TA = – 20 to 70°C)
Parameter
Symbol
Condition
Min
Typ
Input Impedance
RIDTMF
50
—
Detect Signal Level (Each Tone)
– 48
—
Twist (High Group/Low Group)
– 10
—
Frequency Detect Band Width
See Figure 3
± 1.5% ± 2 Hz
—
Frequency Reject Band Width
—
—
DTMF Detect Timing OFF to ON
(See Figure 2)
TVDON
CD1 = 0, CD0 = 1
CD1 = 1, CD0 = 0
—
20
—
30
CD1 = 1, CD0 = 1
—
40
ON to OFF
TVDOFF
CD1 = 0, CD0 = 1
CD1 = 1, CD0 = 0
—
20
—
30
CD1 = 1, CD0 = 1
—
20
Max
Unit
—
dBm
—
3
dB
—
%
1
%
—
—
ms
Max
Unit
15
dB
0.5
dB
1
1
Max
—
0
10
—
± 3.5
—
—
—
—
—
—
Unit
kΩ
dBm
dB
% fc
ms
MOTOROLA
MC145740
3