SA545
SA545
10
9
4
5
12
3
6
7
11
1
SA54L5
10
9
4
5
14
3
6
7
13
1
Designation
V
DD
V
SS
OSC OUT
OSC IN
MUTE
MASK
FILT IN
FILT OUT
MF OUT
IMP
Description
Positive Supply input
Negative Supply input
Connections for 560KHz ceramic resonator
Active high output during keying and tone transmission.
(See Note 1)
Output to disable speech circuit during pulse dialling
and recall. (See Note 2)
Unity gain amplifier input and output for DTMF tone
filtering
DTMF output
'Loop disconnect' dialling output. During dialling, a
logic 1 (high level) correponds to loop connection while
a logic 0 (low level) corresponds to loop disconnection.
LD/DTMF selection, IDP and B:M ratio programming
Column output connections for 16 button single contact
keypad
2
13
14
15
20
16
17
18
19
8
-
2
15
16
17
22
18
19
20
21
8
11
SELECT
C1
C2
C3
C4
R1
R2
R3
R4
HSW
LOCK
Row input connections for 16 button single contact
keypad
Hookswitch input. A logic 1 (High) applied to this input
indicates an "off-hook" condition.
Lock Input must be tied to V
SS
to disable all keypad keys
(except TBR and LNR). Normal operation is enabled by
connecting LOCK to V
DD.
No connection
-
12
N/C
Note 1: The MUTE output is provided to disable the microphone (via the speech
network) while maintaining the loop condition during DTMF transmission.
Note 2: The MASK output may be used to disconnect the whole speech circuit in order
to maintain the break condition whilst on-hook, during a Timed Break Recall
(TBR) operation or LD dialling.
Table 1: Pin Description
6/18
sames
SAMES [ SAMES ]
