as2574b austriamicrosystems, as2574b Datasheet - Page 8

• Manufacturer Part Number: as2574b
• Description: 20 Number One Touch Dialler With Serial Bus For Display Driver
• Manufacturer: austriamicrosystems

Data Sheet
Diode Options
System Considerations
The device is intended to be used in telephone instru-
ments, that are permanently on-line, i.e. also when on-
hook the circuit is connected to the telephone line, but in
standby mode (idle) and hence only drawing a small
leakage current from the line.
This implementation offers new features like electronic
hook switch and call progress monitoring (on-hook
dialling).
Call progress monitoring (CPM) means pressing the LS
key will switch the telephone on from standby (direct
´wake-up´from keyboard) and will present the dialling
tones via a loudspeaker without lifting the handset.
Rev. 1
Row 5
Option
MODE
ACP
NoP
M/B
MS
FT
1
NoP
Column
1
2
3
4
5
6
2
FT
Function
Number of Pulses
Flash Time
Memory Size
Make/Break Ratio
Automatic Call Progress
Default Signalling Mode
3
Columns
MS
4
Digit 1
M/B
8
2
3
4
5
6
7
8
9
0
Furthermore, it is also possible to invoke the CPM by
pressing the LNR, MEM or M1 - 9 when the ACP
(Automatic Call Progress) is activated (diode 5).
Procedure Principles
The procedures for utilizing the features of the device are
optimized out of consideration for the human factor
in order to:
- meet the user´s expectations
- be easy to learn and relearn
- not invoke any automatic functions which the user
- protect the user from committing critical errors, e.g.
- be consistent, simple and usable.
5
doesn’t expect
dialling wrong numbers, deleting stored numbers, etc.
ACP
101.2 ms
33/66 ms
No diode
Standard
MF
10
10
no
6
1
2
3
4
5
6
7
8
9
MODE
40/60 ms
600 ms
diode
yes
NZ
LD
10
20
9
8
7
6
5
4
3
2
1
The diode options
are scanned by
POR and low to
high transition on
HS.
AS2574B
Jan. 1995