SANYO LC737212M Datasheet

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: VDD= 1.5 to 5.5 V — DTMF mode: VDD= 2.0 to 5.5 V

• Low power operation — Pulse mode: IDD= 0.5 mA max (VDD= 3.0 V) — DTMF mode: IDD= 1.0 mA max (VDD= 3.0 V)

• Low standby current —IDR= 0.5 µA max (VDD= 1.0 V)

CMOS LSI

Ordering number : EN5203203

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

Package Dimensions

unit: mm unit: mm

3170-DIP36S 3129-MFP36SD

No. 5203-2/27

LC737212, 737212M

SANYO: DIP36S

[LC737212]

SANYO: MFP36SD

[LC737212M]

Specifications

Absolute Maximum Ratings at Ta = 25°C

Allowable Operating Ranges at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

Maximum power supply voltage V

max –0.3 to +6.5 V

Maximum input voltage V

max –0.3 to VDD+0.3 V

Maximum output voltage V

OUT

max –0.3 to VDD+0.3 V Allowable power dissipation Pd max Ta ≤ 70 ˚C 250 mW Minimum load resistance P

min Between the DTMF and VSSpins 1 kΩ Operating temperature Topr –30 to +70 °C Storage temperature Tstg –40 to +125 °C

Parameter Symbol Conditions min typ max Unit

Supply voltage

DDP

Pulse mode 1.5 5.5 V

DDT

DTMF mode 2.0 5.5 V

Input high-level voltage V

All input pins 0.7 V

Input low-level voltage V

All input pins V

0.3 V

Key contact resistance R

3.0 kΩ

Keypad capacitance C

330 pF

Oscillator element rating

f Center frequency = 3.579545 MHz –1.3 +1.3 %

100 Ω

Electrical Characteristics at Ta = 25°C, fosc = 3.579545 MHz

AC Characteristics at Ta = 25°C, fosc = 3.579545 MHz

No. 5203-3/27

LC737212, 737212M

Parameter Symbol Conditions min typ max Unit

Operating current drain

DDP

Pulse output mode, outputs open, VDD= 3.0 V 0.3 0.5 mA

DDT

DTMF output mode,outputs open, VDD= 3.0 V 0.5 1 mA

Static current drain I

DD(ST)

Standby mode, outputs open, VDD= 1.5 to 5.5 V 1 µA

Memory retention voltage V

Between VDDand V

1 V

Memory retention current I

VDD= 1 V 0.5 µA The SOUT-ENA, OFF-HOOK, DPR, P/T, BMR,

IH1

ON-HOOK-DIAL IN, HOLD-OFF IN, DISCON IN, 1 µA

Input pin current

SI/KEY, OFF/ON-HOOK, and STORE pins, VIH= V

The SOUT-ENA, OFF-HOOK, DPR, P/T, BMR,

IL1

ON-HOOK-DIAL IN, HOLD-OFF IN, DISCON IN, –1 µA SI/KEY, OFF/ON-HOOK, and STORE pins, VIL= V

ILK1

All key pins, VDD= 1.5 V, V

ILK

= V

–20 µA

ILK2

All key pins, VDD= 5.5 V, V

ILK

= V

–300 µA

Key pin current

OLK1

All key pins, VDD= 1.5 V, V

OLK

= 0.4 V 200 µA

OLK2

All key pins, VDD= 5.5 V, V

OLK

= 0.4 V 0.7 mA

Output pin leakage current I

OFF

VO= VDD, VDD= 5.5 V, with the output off, the DP,

1 µA

MUTE1, MUTE2, and S-OUT pins.

OH1

The K-TONE, HOLD-OUT, HOOK-CTL,

– 0.5 V

and SP-CTL pins, VDD= 1.5 V, IOH= –250 µA

OH2

The K-TONE, HOLD-OUT, HOOK-CTL,

– 1 V

Output pin voltage

and SP-CTL pins, VDD= 5.5 V, IOH= –1 mA

OL1

The K-TONE, DP, MUTE1, MUTE2, SP-CTL,

0.4 V

HOLD-OUT, and HOOK-CTL pins, V

= 1.5 V, IOL= 250 µA

OL2

The K-TONE, DP, MUTE1, MUTE2, SP-CTL,

0.4 V

HOLD-OUT, and HOOK-CTL pins, V

= 5.5 V, IOL= 1 mA

Parameter Symbol Conditions min typ max Unit

Key debounce time T

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

1035.7 HZ

Key tone output time T

30.9 ms

In Pulse mode at 10 pps 3.88 3.9 3.93 s

Auto-pause time T

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

700 710 720 ms

Hooking pause time T

HKP

0.98 1.0 1.02 s

Memory store confirmation

KST

2071.4 Hz

tone frequency Memory store confirmation

KSTON

278.1 ms

tone output time Low tone amplitude V

VDD= 3.5 V, RL= 10 kΩ 165 200 240 mVrms

Tone output ratio dBCR V

= 2.0 to 5.5 V, RL= 10 kΩ 1 2 3 dB Tone output distortion DIS V

= 2.0 to 5.5 V, RL= 10 kΩ 10 % Oscillator start time T

START

VDD= 1.5 to 5.5 V 30 ms V

= 3.0V 1 ms

Pulse Dialing Output/fosc = 3.579545 MHz

DTMF Output/fosc = 3.579545 MHz

Pin Assignment

No. 5203-4/27

LC737212, 737212M

Dialing Interdigit Make

DPR pin BMR pin

pulse rate pause percent

9.94 pps 834.2 ms 33.2%

19.89 pps 525.2 ms 33.2%

9.94 pps 834.2 ms 39.2%

19.89 pps 525.2 ms 39.2%

Input

Output frequency [Hz]

Deviation [%]

Standard LC737212 R1 697 697.0 +0.01 R2 770 770.1 –0.02 R3 852 852.3 –0.03 R4 941 942.0 –0.11 C1 1209 1209.3 –0.03 C2 1336 1335.7 +0.03 C3 1477 1476.7 +0.02 C4 1633 1633.0 +0.00

Top view

Block Diagram

No. 5203-5/27

LC737212, 737212M

Keypad Layout

Key Matrix Functions (when the SOUT-ENA pin is high)

Digits 1 to 9, 0: Dialing data * and #: DTMF dialing data

In pulse mode, the * key switches the LC737212/M to DTMF mode. F: Flash (0.71 second) M: Quick-dialing address specification (only in the on-hook state, sets up memory store mode) R/P: Redial, pause (3.9 seconds), clear the paused state HOLD ON/OFF: Controls the on/off state of hold mode STORE: Sets up memory store mode. A1 to A5: One-touch dialing key 00 to 17: 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

LC737212, 737212M

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

* 0 #

HOLD

03 08 13 A4

ON/OFF

A1 A2 A3 STORE 04 09 14 A5

C1 to C8

Memory readout

Memory store

• R/P key After connecting to the line, the R/P functions as a redial key as long as the system has not performed a dialing output operation. In manual dialing mode, the R/P key functions as the pause data key. When dialing from memory: — During a pause operation: Cancels the pause — While dialing: Inserts a pause During a redial operation: — During a pause operation: Cancels the pause — While dialing: Ignored If two or more pause characters occur in the data, the pause cancel operation will cancel all pending pauses in a single operation.

• STORE key Pressing the STORE key sets the system to memory store mode. Pressing the STORE key again during a memory store operation cancels all input data.

• HOLD ON/OFF key Controls the on/off state of off-hook mode. No key tone is output at this time.

• Keys A1 to A5 These are the one-touch auto-dialing keys. Pressing one of these keys outputs the corresponding memory data from the DP and DTMF pins.

• Keys 00 to 17 These are user-defined keys. When one of these keys is pressed, the LC737212/M outputs the corresponding status and key code from the serial interface.

No. 5203-7/27

LC737212, 737212M

No. 5203-8/27

LC737212, 737212M

Pin Functions

Pin No. Symbol Function

1 C5 Column input 2 R1 3 R2 4 R3 Row input 5 R4 6 R5 7 SOUT-ENA Serial output enable, H: enable, L: disable 8 HOLD-OFF IN Hold mode clear input; falling edge detection.

9 ON-HOOK DIAL IN On-hook dialing input; falling edge detection 10 SI/KEY Serial input/keypad input switching 11 ON-HOOK Hook-switching input 12 DPR Dialing pulse rate switching; H: 20 pps, L: 10 pps 13 R/T Pulse/tone switching; H:pulse, L: tone 14 BMR Make percentage switching input; H: 33%, L: 39% 15 XIN

Oscillator circuit. Connect either a crystal or ceramic oscillator element with a

16 XOUT

frequency of 3.58 MHz between these pins.

17 OFF/ON-HOOK STORE Off-hook store/on-hook store switching 18 V

Power supply

19 V

20 SP-CTL Speaker reception control output; complementary output 21 DTMF DTMF output; npn emitter-follower output 22 MUTE2 DTMF mute output; n-channel open drain output 23 MUTE1 DP and K-TONE muting output; n-channel open drain output 24 S-OUT Serial data output; n-channel open drain output 25 DP Dialing pulse output; n-channel open drain output 26 K-TONE K-tone output; complementary output 27 HOOK-CTL Hook control output; complementary output 28 HOLD-OUT Hold mode output; complementary output 29 DISCON IN Disconnect input 30 C1 31 C6 32 C7 33 C2 Column inputs 34 C8 35 C3 36 C4

• SOUT-ENA Normaly set high. Serial output and Dial output are enabled when this pin is set high.

• HOLD OFF IN Hold mode is cleared when a falling edge is detected on this pin. HOLD-OFF pin inputs are not accepted for the 0.5 seconds immediately following a transition to on-hook hold mode.

• ON-HOOK-DIAL IN This pin toggles an on/off state on each input falling edge. When the telephone is on hook, this pin toggles the on/off state of on-hook dialing mode. When the telephone is off hook, this pin toggles the on/off state of monitor mode.

• SI/KEY The keypad is set to input mode when this pin is set low. When this pin is set high, serial input is enabled. In this state, all keypad inputs are pulled up by built-in resistors, and the pins C6 to C8 function as the serial interface input pins.

C6 = serial clock input C7 = serial data input C8 = strobe input

• OFF-HOOK This pin is the hook state switching input.

• DPR This pin is the dialing pulse rate switching input. (H: 20 pps, L: 10 pps)

• P/T

This pin is the dialing signal switching input. (H: pulse, L: DTMF) This pin can only switch from pulse to DTMF. This

allows mixed-mode dialing, i.e. switching modes during dialing.

• DISCON IN Setting this pin low switches the LC737212/M to low power mode and forcibly stops the oscillator circuit. All outputs are turned off in low power mode. (The n-channel open-drain outputs go to the high-impedance state, and the complementary outputs go low.) The internal states of the LC737212/M are reset when this pin goes high.

We recommend setting the DISCON pin low when power is first applied, and setting it high after the power-supply voltage (VDD) has reached or exceeded 1.5 volts.

• BMR This pin sets the break/make ratio for the dialing pulse output. (H: 33.2%, L: 39.2%)

• OFF/ON-HOOK STORE This pin switches the memory storing mode. H: Off-hook store (Memory stored with the telephone line connected.) L: On-hook store (Memory stored with the telephone line disconnected.)

No. 5203-9/27

LC737212, 737212M

Off-hook input On-hook Dial input Status

H H STANDBY H L ON-HOOK DIAL L H OFF-HOOK DIAL L L MONITOR

1 to 10 kΩ

0.1 to 10 µF

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