CD22859 Datasheet, PDF (4/5 Pages) Intersil Corporation – Monolithic Silicon COS/MOS Dual-Tone Multifrequency Tone Generator

CD22859
COL 1 COL 2 COL 3 COL 4
ROW 1
1
2
3
A
697 (699.1)
ROW 2
4
5
6
B
770 (766.2)
ROW 3
7
8
9
C
852 (847.4)
ROW 4
*
0
#
D
941 (948.0)
1209 1336 1477 1633
(1215.9) (1331.7) (1471.9) (1645.0)
NOMINAL
OUTPUT
FREQUENCY
FIGURE 1. BELL AND NOMINAL OUTPUT FREQUENCIES (IN PARENTHESIS) FOR 3.579545MHz CRYSTAL
DTMF GENERATOR FUNCTIONAL TRUTH TABLE
INPUTS
OUTPUTS
NUMBER OF
NUMBER OF ROW IN-
COLUMN INPUTS AC-
PUTS ACTIVATED
KEYBOARD MODE
TIVATED “LOW”
“LOW”
CD
X
X
X
“0”
TONE
None
OSC RUN-
NING
R_X
T_X
No
“0”
“0”
No Key Depressed
0
0
“1”
None
No
“0”
“0”
0
1, 2, 3, or 4
1
“1”
Dual Tone R_A, C₁
Yes
“1”
“1”
0
“1”
None
No
“0”
“0”
Normal Dialing
1
One Key Depressed
(Note 9)
1
“1”
Dual Tone R_A, C_B
Yes
“1”
“1”
Two or More Keys In
Same Row
(Note 10)
2, 3, or 4
1
“1” Single Row Tone R_A
Yes
“1”
“1”
Two or More Keys In
Same Column
Two or More Keys In
Different Rows and
Columns
1
2, 3, or 4
2, 3, or 4
2, 3, or 4
“1” Single Column Tone
Yes
C_B
“1”
None
Yes
“1”
“1”
“1”
“1”
Where:
X = Don’t Care
R_A refers to Tone Output frequencies corresponding to Row 1, Row 2, Row 3, Row 4; C_B refers to Tone Output frequencies corresponding to
Column 1, Column 2, Column 3, Column 4.
A = 1, 2, 3, 4 B = 1, 2, 3, 4 A = B, or A ≠ B
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