NTE NTE1731 Datasheet

NTE1731

Integrated Circuit

CMOS 10 Number Pulse Dialer

Description:

The NTE1731 is a CMOS LSI repertory dialer with ten 16–digit number memory storage in a 16–Lead
DIP type package. The pulse and mute signal outputs resulting from keyboard input are like those
of a pulse dialer. The NTE1731 incorporates a 64 x 10 bit RAM which is used to store the ten tele­phone numbers.

When used in a Public Branch Exchange (PBX) system, a Pause function is provided. This function
suspends dial pulse output upon pause detection (via # key input), and resumes the output after one
of the numeric keys is pressed.

Features:

D Make Ratio: 30/40% Pin Selectable
D Pulse Output: “0” True
D Mute Output: “0” True
D Stores Ten 16–digit Telephone Numbers
D One Temporary Memory and Permanent Memory Storage of Telephone Numbers are Possible
D Uses a CR Oscillator as a Frequency Reference
D Line Operation Off–Hook, Battery Operation On–Hook
D Uses Either a Standard 2–of–7 Matrix Keyboard or a Single Contact Keyboard
D PBX Pause Storage

Absolute Maximum Ratings:

Supply Voltage (Note 1), V

DD

Power Dissipation (Note 2), PD 500mW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maximum Pin Voltage 1 (Note 3), V
Maximum Pin Voltage 2 (Note 4), V
Operating Temperature Range, T
Storage Temperature Range, T

in1
in2

opr

–55° to +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

stg

–30° to +50°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Note 1. Referenced to GND
Note 2. TA = +25°C
Note 3. The Maximum applicable voltage on any pin with respect to GND
Note 4. The maximum applicable voltage on any pin with respect to V

DD

Recommended Operating Conditions:

Supply Voltage, V

DD

2.6V to 6.0V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

–0.3V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

+0.3V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DC Characteristics: (–30°C x TA x =60°C unless otherwise specified)

Parameter Symbol Test Conditions Min Typ Max Unit

Standby Current I
Operating Current I
MUTE Sink Current I
Pulse Sink Current I
MUTE Pulse Leakage Current I

SB
OP
ML
PL

LKG

Key Contact Resistance RK
Keyboard Capacitance CK

“0” Logic Level V
“1” Logic Level V

Key Pull–Up Resistance K
Key Pull–Down Resistance K

VDD = 2.5V, Note 5 – 1.0 5.0 µA
VDD = 2.5V, Note 6 – 100 200 µA
VDD = 2.5V, VO = 0.5V 0.5 2.0 – mA
VDD = 2.5V, VO = 0.5V 1.0 4.0 – mA
VDD = 6V, VO = 6V – 0.001 1.0 µA

1
1

IL

IN

VDD = 4V, Note 7 – 100 – kΩ

RU

VDD = 4V, Note 7 – 5.0 – kΩ

RD

– – 1.0 kΩ
– – 3.0 pF

GND – 0.2V

0.8V

DD

– V

DD

DD

V
V

Note 5. All output pins in no–load condition when clock is stopped in Off–Hook mode.
Note 6. All output pins in no–load condition during key input, in either On–Hook or Off–Hook Mode.
Note 7. Resistance when ROW and COL pins are scanned at 125Hz and at high or low level.

AC Characteristics:

Parameter Symbol Test Conditions Min Typ Max Unit

Oscillator Frequency f

OSC

Key Debounce Time t
Oscillator Start–Up Time t
Pulse Rate P
Break Time t

DB
OS

Note 8 – 480 – kHz
Note 9, Note 10 – 32 – ms

– – 8.0 ms

Note 10 – 10 – pps

R

Pin9 = VDD, Note 10 – 60 – ms

B

Pin9 = GND, Note 10 – 68 – ms
Inter–Digital Pause Time t
Mute Overlap Time t

IDP

MOL

Note 10 – 840 – ms

Note 10 – 2 – ms

Note 8. Use elements with the following characteristics as the ceramic oscillator:

R < 20Ω, RA ≥ 70KΩ, CO ≤ 500pF.
Note 9. Key input is accepted if it is valid 32msec after the start of oscillation.
Note 10 . Changes in proportion to the frequency of the oscillator.

Functional Description:
Dialed Number Memory

During normal dialing, each digit is stored in the LND (Last Number Dialed) buffer, location 0. The
telephone number dialed can be left in this temporary LND buffer for later use or it can be copied into
any of the other nine permanent memory locations.

Telephone numbers to be automatically dialed by the NTE1731 may be entered into the LND buffer
while either On–Hook or Off–Hook.

Dialed Number Memory (Cont’d)

However, the NTE1731 must be in On–Hook mode for a number to be copied into a permanent
memory location. A number may be copied and stored by entering the key sequence

N∗∗