SA589 Datasheet, PDF (2/14 Pages) Sames – LD/DTMF SWITCHABLE DIALLERS WITH DEDICATED KEYS FOR 20 MEMORIES

SA589 FAMILY
TABLE 1: PIN FUNCTIONS
Pin
number
Pin
name
Function
1
NC
Not connected
3
IMP
'Loop disconnect' dialling output
4
SELECT LD/DTMF selection, IDP and B/M ratio programming
5
MASK Output to disable speech circuit during pulse dialling and recall
(see note 1)
6
OSC OUT Connections for 560kHz ceramic resonator
7
OSC IN
8
FILT IN Unity gain amplifier input and output for DTMF tone filtering
9
FILT OUT
10
HSW
Hookswitch input - a logic 1 at this pin is used to indicate 'Off-
Hook'
11
V_SS
Negative supply
12
V
Positive supply
DD
13 PAUSE OUT Active high indicating a pause when dialling from memory
17
MF OUT Unfiltered DTMF output
18
MUTE Output active during keying and tone transmission (see note 2)
19
COL1
20
COL2
21
COL3
26
COL4
27
COL5
2
COL6
16
COL7
22
ROW1 Connections for 38 key single contact keypad
23
ROW2
24
ROW3
25
ROW4
14
ROW 5
15
ROW 6
28
ROW 7
1. MASK may be used to disconnect the whole speech circuit in order to maintain the break
condition whilst on-hook and during a TBR (Timed Flash) operation.
2. MUTE is provided to disable the microphone while maintaining the loop during DTMF
transmission.
OPERATION
Power-on
When power is applied to the chip, a power-on reset circuit operates and ensures that the
Memories are cleared and all logic is reset. The power-on reset circuit is designed such that
if the chip supply voltage drops to a level at which the memories may be corrupted, it will
always, under all conditions, clear the memory, so that corrupt data is not retained.
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