LC737212 Datasheet, PDF (6/27 Pages) Sanyo Semicon Device – Telephone Dialer IC with On-Chip Memory for Push- Button Telephones

LC737212, 737212M
Keypad Layout
R1
1
2
3
F
00
05
10
15
4
5
6
M
01
06
11
16
7
8
9
R/P
02
07
12
17
to
*
0
#
HOLD
03
08
13
A4
ON/OFF
R5
A1
A2
A3
STORE
04
09
14
A5
C1
to
C8
Key Matrix Functions (when the SOUT-ENA pin is high)
Digits 1 to 9, 0:
* and #:
F:
M:
R/P:
HOLD ON/OFF:
STORE:
A1 to A5:
00 to 17:
Dialing data
DTMF dialing data
In pulse mode, the * key switches the LC737212/M to DTMF mode.
Flash (0.71 second)
Quick-dialing address specification (only in the on-hook state, sets up memory store mode)
Redial, pause (3.9 seconds), clear the paused state
Controls the on/off state of hold mode
Sets up memory store mode.
One-touch dialing key
Definable function keys
The keypad is formed as a matrix using the key input pins (R1 to R5 and C1 to C8) and supports 40 keys. A given key is
input by shorting or grounding the column pin and the row pin for that key. To prevent discharge of the backup battery
due to inadvertent key presses in standby mode (when the circuit is disconnected from the telephone line), key input by
shorting is not accepted. This means that if on-hook storing of telephone numbers in memory is selected, the application
must implement STORE key (or M key) input by grounding the ROW pin and COLUMN pin.
• Digit keys (1 to 9 and 0)
— Dialing data keys
— Quick-dialing memory address specification keys
• * and # keys
— DTMF mode: The * and # keys function as dial data keys
— Pulse mode:
* ... Pulse/tone switching key
# ... Unused.
• F key (flash key)
Invokes an operation equivalent to 0.71-second hooking implemented by turning on the DP output for 0.71 second.
Although a 1-second pause is automatically inserted, the following dialing data may be entered during that period.
Redialing is possible after a flash operation.
• M key (memory key)
When on-hook memory registration is set up, the system switches from standby mode to memory registration mode
when the M key is pressed. The address of the dialing memory is specified by combination of the digit keys that are
pressed immediately after the M key. The system operates as follows when the memory address operation is performed
incorrectly.
No. 5203-6/27