SA541 Datasheet, PDF (6/16 Pages) Sames – PULSE/DTMF SWITCHABLE DIALLERS

SA541
SA541
10
9
4
5
12
SA54L1
10
9
4
5
14
Designation
V_DD
V_SS
OSC OUT
OSC IN
MUTE
3
and
6
7
11
1
2
13
14
15
20
16
17
18
19
8
3
MASK
6
FILT IN
7
FILT OUT
13
MF OUT
1
IMP
2
SELECT
15
C1
16
C2
17
C
22
C4
18
R1
19
R2
20
R3
21
R4
8
HSW
-
11
LOCK
-
12
N/C
Description
Positive Supply input
Negative Supply input
Connections for 560KHz ceramic resonator
Active high output during keying, tone transmission and
MUTE key depression. (See Note 1)
Output to disable speech circuit during pulse dialling
recall. (See Note 2)
Unity gain amplifier input and output for DTMF tone
filtering
DTMF output
'Loop disconnect' dialling output.
LD/DTMF selection, IDP and B:M ratio programming
Column output connections for 16 button single contact
keypad
Row input connections for 16 button single contact
keypad
Hookswitch input. A logic 1 (High) indicates an “off-
hook” condition
Lock Input must be tied to V_SS to disable all keypad keys
(except TBR, LNR and MUTE). Normal operation is
enabled by connecting LOCK to V_DD.
No connection
Note 1: The MUTE output is provided to disable the microphone 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 mantain the break condition whilst on-hook, during a Timed Break Recall
(TBR) operation or LD dialling.
Table 1: Pin Description
6/16
sames