FX623 Datasheet, PDF (3/6 Pages) List of Unclassifed Manufacturers – Call Progress Tone Decoder

Application Information
V_DD
C₅
V_SS
Q3
DATA CHANGE
DATA OUTPUTS
1
16
C₁
A HEX Code
Q2
Output representing
2
CS
15
the decoded tone
Q1
frequency
3
14 ^IRQ
See Table 1
Q0
4
13 ^{P U R S}
V_DD
5
FX623P
12
HOLD
COMPOSITE SIGNAL IN
SIGNAL IN
6
11 ^VSS
C₂
7
XTAL
8
XTAL/CLOCK
10
9
R₁
X₁
C₃
R₂
C₄
V_SS
Fig.2 Recommended External Components
Hex Output Code
Character Q3 Q2 Q1 Q0
Band Edges (Hz) Nominal
Lower Upper Centre
Edge Edge Freq.
0
0000
364
386
375
1
0001
488
520
500
2
0010
520
580
550
3
0011
580
618
600
4
0100
386
412
400
5
0101
412
436
425
6
0110
436
463
450
7
0111
463
487
475
8
1000
900
1008
950
9
1 0 0 1 1273 1325 1300
A
1 0 1 0 1350 1455 1400
B
1 0 1 1 1750 1855 1800
C
1 1 0 0 2062 2140 2100
D
1101
frequency not guaranteed
E
1110
frequency not guaranteed
F
1111
NOTONE
Table 1 Tone Decode Frequencies
Component
R₁
R₂
C
1
C₂
C₃
C₄
C₅
X
1
Tolerances R = ±10%
Value
1.0MΩ
1.0MΩ
47.0nF
4.7nF
33.0pF
33.0pF
1.0µF
3.579545MHz
C = ±20%
Timing Information
With CS Low - Figure 3.
After initial power-up and the Hold input inactive
(High), as frequencies are input, with the Data Change
output as an active (High) indicator, the data is
presented at the Data Outputs.
If/when the Hold input is placed active (Low), the
data at the Data Outputs is frozen and the Data
Change output held High at its next active excursion -
until the Hold input is returned High.
With the Hold input held High - Figure 4.
As frequencies are input a correct decode will
produce an active (Low) interrupt level.
This interrupt (IRQ) is serviced and reset by an
active (Low) CS input.
Note the ‘valid data’ period at the Data Outputs.
3