Overview
The LC737212 and LC737212M are CMOS LSI
telephone dialers for pushbutton telephones. They support
both DTMF and pulse dialing. These products include 25
16-digit memories for storing telephone numbers and one
63-digit memory for redialing, and they provide, in a
single chip, all the functions required for dialing and
control for a standard independent telephone, including
on-hook dialing and a hold function. They also provide a
serial I/O interface for connection to a microcontroller.
Functions
Fabrication in a CMOS process that allows these circuits
to be directly operated from a telephone line
Support for single-contact keypads
Built-in oscillator circuit (fosc = 3.58 MHz) that can
drive either a standard color-TV crystal oscillator
element or a ceramic resonator
High-precision DTMF signal
Frequency generator circuit (0.1%) adopted for eased
ceramic resonator selection
Five one-touch 16-digit auto-dial memories and 20
quick-dialing memories
On-hook or off-hook can be specified for memory
entries.
Mode change and pause data items can be stored in the
dialing memories.
63-digit redial memory
Automatic pause (3.9 seconds) insertion when the mode
is switched.
Automatic pause (1.0 second) insertion after a flash
operation.
Mode changing is one-directional, from pulse mode to
tone mode.
Output of a key press tone (1036 Hz, 31 ms) for keys
other than DTMF keys when key input is valid
Output of an operation complete confirmation tone
(2072 Hz, 279 ms for each telephone number) when a
telephone number is stored in memory
Generates 12 signal types in DTMF mode.
Supports an on-hook dialing mode.
Supports a hold function with hold mode.
Supports both 10 and 20 pps dialing pulse rates.
The mode can be switched from either the P/T pin or by
a key input.
Settable dialing pulse circuit closed ratio (make
percent): either 33% or 39%.
Supports either keypad or serial input.
Provides serial output of the keypad input data and the
internal status.
Capable of controlling the serial output timing.
Supports 18 user-defined keys.
Wide operating power-supply voltage range
-- Pulse mode: V
DD
= 1.5 to 5.5 V
-- DTMF mode: V
DD
= 2.0 to 5.5 V
Low power operation
-- Pulse mode: I
DD
= 0.5 mA max (V
DD
= 3.0 V)
-- DTMF mode: I
DD
= 1.0 mA max (V
DD
= 3.0 V)
Low standby current
-- I
DR
= 0.5 A max (V
DD
= 1.0 V)
CMOS LSI
Ordering number : EN5203
203
21398RM(OT) No. 5203-1/27
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
Telephone Dialer IC with On-Chip Memory for Push-
Button Telephones
LC737212, LC737212M
Electrical Characteristics
at Ta = 25C, fosc = 3.579545 MHz
AC Characteristics
at Ta = 25C, fosc = 3.579545 MHz
No. 5203-3/27
LC737212, 737212M
Parameter
Symbol
Conditions
min
typ
max
Unit
Operating current drain
I
DDP
Pulse output mode, outputs open, V
DD
= 3.0 V
0.3
0.5
mA
I
DDT
DTMF output mode,outputs open, V
DD
= 3.0 V
0.5
1
mA
Static current drain
I
DD(ST)
Standby mode, outputs open, V
DD
= 1.5 to 5.5 V
1
A
Memory retention voltage
V
DR
Between V
DD
and V
SS
1
V
Memory retention current
I
DR
V
DD
= 1 V
0.5
A
The SOUT-ENA, OFF-HOOK, DPR, P/T, BMR,
I
IH1
ON-HOOK-DIAL IN, HOLD-OFF IN, DISCON IN,
1
A
Input pin current
SI/KEY, OFF/ON-HOOK, and STORE pins, V
IH
= V
DD
The SOUT-ENA, OFF-HOOK, DPR, P/T, BMR,
I
IL1
ON-HOOK-DIAL IN, HOLD-OFF IN, DISCON IN,
1
A
SI/KEY, OFF/ON-HOOK, and STORE pins, V
IL
= V
SS
I
ILK1
All key pins, V
DD
= 1.5 V, V
ILK
= V
SS
20
A
I
ILK2
All key pins, V
DD
= 5.5 V, V
ILK
= V
SS
300
A
Key pin current
I
OLK1
All key pins, V
DD
= 1.5 V, V
OLK
= 0.4 V
200
A
I
OLK2
All key pins, V
DD
= 5.5 V, V
OLK
= 0.4 V
0.7
mA
Output pin leakage current
I
OFF
V
O
= V
DD
, V
DD
= 5.5 V, with the output off, the DP,
1
A
MUTE1, MUTE2, and S-OUT pins.
V
OH1
The K-TONE, HOLD-OUT, HOOK-CTL,
V
DD
0.5
V
and SP-CTL pins, V
DD
= 1.5 V, I
OH
= 250 A
V
OH2
The K-TONE, HOLD-OUT, HOOK-CTL,
V
DD
1
V
Output pin voltage
and SP-CTL pins, V
DD
= 5.5 V, I
OH
= 1 mA
V
OL1
The K-TONE, DP, MUTE1, MUTE2, SP-CTL,
0.4
V
HOLD-OUT, and HOOK-CTL pins, V
DD
= 1.5 V, I
OL
= 250 A
V
OL2
The K-TONE, DP, MUTE1, MUTE2, SP-CTL,
0.4
V
HOLD-OUT, and HOOK-CTL pins, V
DD
= 5.5 V, I
OL
= 1 mA
Parameter
Symbol
Conditions
min
typ
max
Unit
Key debounce time
T
KD
30
ms
Pin chatter exclusion time
T
PCHT
OFF-HOOK, P/T, ON-HOOK-DIAL, IN HOLD OFF IN
45
ms
Key scan frequency
f
KSC
258.9
HZ
Key tone frequency
f
KT
1035.7
HZ
Key tone output time
T
KT
30.9
ms
In Pulse mode at 10 pps
3.88
3.9
3.93
s
Auto-pause time
T
AP
In Pulse mode at 20 pps
3.88
3.9
3.93
s
DTMF mode
3.88
3.9
3.93
s
DTMF output time
T
MFON
98
100
102
ms
DTMF interdigit pause time
T
MFOFF
93
95
97
ms
Hooking time
T
HK
700
710
720
ms
Hooking pause time
T
HKP
0.98
1.0
1.02
s
Memory store confirmation
f
KST
2071.4
Hz
tone frequency
Memory store confirmation
T
KSTON
278.1
ms
tone output time
Low tone amplitude
V
OR
V
DD
= 3.5 V, R
L
= 10 k
165
200
240
mVrms
Tone output ratio
dBCR
V
DD
= 2.0 to 5.5 V, R
L
= 10 k
1
2
3
dB
Tone output distortion
DIS
V
DD
= 2.0 to 5.5 V, R
L
= 10 k
10
%
Oscillator start time
T
START
V
DD
= 1.5 to 5.5 V
30
ms
V
DD
= 3.0V
1
ms
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