TP5088 Datasheet, PDF (4/6 Pages) National Semiconductor (TI) – TP5088 DTMF Generator for Binary Data

TABLE II Functional Truth Table
Keyboard
Data Inputs
TONE
TONES OUT
MUTE
Equivalent
D3
D2
D1
D0
ENABLE
f_L (Hz)
f_H(Hz)
X
X
X
X
X
0
0V
0V
0V
1
0
0
0
1
L
697
1209
OC
2
0
0
1
0
L
697
1336
OC
3
0
0
1
1
L
697
1477
OC
4
0
1
0
0
L
770
1209
OC
5
0
1
0
1
L
770
1336
OC
6
0
1
1
0
L
770
1477
OC
7
0
1
1
1
L
852
1209
OC
8
1
0
0
0
L
852
1336
OC
9
1
0
0
1
L
852
1477
OC
0
1
0
1
0
L
941
1336
OC
1
0
1
1
L
941
1209
OC
1
1
0
0
L
941
1477
OC
A
1
1
0
1
L
697
1633
OC
B
1
1
1
0
L
770
1633
OC
C
1
1
1
1
L
852
1633
OC
D
0
0
0
0
L
941
1633
OC
Timing Diagram
Typical Application
FIGURE 2
TL H 5004 – 3
Adjust R_E for desired tone amplitude
FIGURE 3
TL H 5004 – 4
4