as2574b austriamicrosystems, as2574b Datasheet - Page 3
as2574b
Manufacturer Part Number
as2574b
Description
20 Number One Touch Dialler With Serial Bus For Display Driver
Manufacturer
austriamicrosystems
Datasheet
1.AS2574B.pdf
(24 pages)
Data Sheet
Pin Description Continued
Keyboard Layout
Rev. 1
The keyboard is arranged in a 5 x 6 contact matrix with single pole single throw
contacts (SPST).
Keyboard resistance: Ron < 5 k ; Roff > 5 M .
Pin #
28
24
25
26
27
1
2
3
4
5
L S
1
1
*
4
7
Pin Node
TONE
Vdd
Vss
HS
TB
LNR
2
2
5
8
0
Description
Hook switch input; active high with internal pull-down resistor. Debounce 25 ms.
Negative terminal of power supply.
Tone burst output:
MF tone output.
An on chip reference voltage provides tone levels independent of the
supply voltage.
A dc path from TONE output is needed to accommodate an external voltage
divider for setting the appropriate tone level.
Frequencies:
Positive terminal of power supply
M9
3
3
6
9
#
LS high
MT high
MT+LS high
Frequency (Hz)
COLUMN
1209
1336
1477
1633
697
770
852
941
RECALL
ENTER
MUTE
MEM
2ND
4
3
80 ms burst, 2 sec pause
80 ms burst, 8 sec pause
80 ms burst, 2 sec pause
Key Matrix (Hz)
M10
M1
M2
M3
M4
see p. 7
5
row 1
row 2
row 3
row 4
col. 1
col. 2
col. 3
M5
M6
M7
M8
6
Error (%)
In off-hook state all keys are
enabled (CD = high)
0.7%
Only in speech mode
Enabled only
when off-hook
Enabled also
when ACP is
active (diode 5
inserted)
Enabled when
CD = high
AS2574B
Jan. 1995