NOVATEK NT91215B, NT91215C, NT91214D, NT91214B, NT91215D Datasheet

Features



One touch redial operation



Tone/Pulse switchable



32 digit capacit y f or r edial i ng



Automati c mixed redialing (last number redial) of pulse
to DTMF with multi ple automatic access pauses



PABX auto-pause is 2.2 seconds



DTMF Timing:
Manual dialing: minimum duration for bursts and
pauses
Redialing: calibr at ed ti ming



Hands-Free control function

General Description

NT91214/15 Series

Tone/Pulse Dialer



Wi de operating vol t age range: 2V to 5.5V



Key-in beep tone output



Digits dialed manually after redialing are cascadable
and stored as additional digits for the next redialing



Uses inexpensive ceramic resonator (3.58 MHz)



Two versions for different telephone systems



Built-in power up reset circuit



Four extra function keys: flash, pause, redial and DP

or

DTMF mixed dialing



4 x 4 (or 2 x 8) keyboard can be used



Low standby current

The NT91214/15 is a single-chip, silicon gate, CMOS
integrated circuit with an on-chip oscillator for a 3.58MHz
crystal or ceramic r esonator. It pr ovides a dialing pul se
(DP) or dual tone multi-frequency (DTMF) dialing. A
standard 4 x 4 mat rix keyboard can be used to support
either DP or DTMF modes.

Up to 32 digits can be saved in the on-chip RAM for
redialing. In the DTMF mode, a short minimum tone
duration and minimum intertone pause allows rapid
dialing. Maximum tone duration depends on the key
depression time during manual dialing.

Pin Configurations

a. 16-Pin Package b. 18-Pin Packages c. 20-Pin Package

(i) Key Tone Output (ii) Hands-Fr ee Cont r ol

1V1.0

Keyboard Assignments

NT91214/15 Series

123F1

456F2

789 P

*/T 0 # RD

C1 C2 C3

1. */T -- In PULSE mode this key works as Pulse → DTMF key (T key). In DTMF mode the key works as * key.
*/T key will occupy one memory digit in either use.

2. F1 -- Flash key. The break time is 297 ms or 96 ms (NT91214/15 respectively)

3. F2 -- Flash key for break time 640 ms

4. P -- Pause key (2.2 seconds)

5. RD -- One key redial key

6. # -- In PULSE mode this key input is neglected. In DTMF mode this key works as # key.

GND

R1

R2

R3

R4

Block Diagram

V1.02

NT91214/15 Series

Absolute Maximum Ratings*

Supply Voltage (VDD). . . . . . . . . . . . . . . . . . . .≤ 6.0V

IN

Input Voltage (V
Output Voltage (V

Output Vol tage (V
Tone Output Current (I
Power Dissipation (P

Operating Temperature (Top). . . . . . . -20°C to +70°C

Storage Temperature ( Tstg). . . . . . . - 40°C to +150°C

DC Electrical Characteristics

Parameter Symbol Min. Typ. Max. Unit Conditions

Operating Voltage VDD

Memory Retention Voltage V

Memory Retention Current I

) . . . . . . . VSS - 0. 3V t o VDD + 0. 3V

OUT

) . . . . VSS - 0.3 V to VDD + 0. 3 V

OUT

)(DP,

D

XMIT MUTE

TONE

) . . . . . . . . . . . . . . ≤50mA

) . . . . ≤1.2V

) . . . . . . . . . . . . . . . . . ≤500mW

(VDD = 3.5V, VSS = 0V, Fosc = 3. 579MHz, Top = 25°C)

2.0 5.5

2.0 5.5 TONE mode

MR

MR

1V -

0.05 0.4

*Comments

Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent damage to this device.
These are stress ratings only. Functional operation of
this device at these or any other conditions above those
indicated in the operational sections of this specification
is not implied or intended. Exposure to the absolute
maximum rating conditions for extended periods may
affect device reliability.

Test
KT.

PULSE mode

V

HK

µ

VDD = 1.0V,

A

All outputs unl oaded

= VDD

A

-

DDP

Operating Current

I

I

DDT

Standby Current Iso

Input Current

V

V

R1

- R4 Input Current

Tone out Voltage

I

V

V

HFI

Pull Low Current

HFI



I

R

OC

OR

0.32 1.0
mA

0.6 2.0 Tone mode

0.03 0.05

µ

A

Pulse mode

HK

= VDD = 1.5V

All outputs A
unloaded

All outputs
unloaded,

A

no key

HK

0.5 10

IH

IL

0.8 1
VDD

00.2

115

584 730 876

µ

A

mVp-p

= VSS

Column

456 570 684 Row

VDD = 3.5V (Note 1)



5

µ

A

HFI

pin connected to 0V

selected

VDD = 3.5V D

L

R

= 5K

C

B

V1.03

DC Electrical Characteristics (continued)

NT91214/15 Series

Parameter Symbol Min. Typ. Max. Unit Conditions

HFO Dri v e Cur r ent

HFO, KT, MODEOUT

XMITMUTE

DP

Sink Current

Sink Current

OH1





I

OL1

I

OL2

I

0.4 2 mA

0.9 5.3 mA

1.1 5.3 mA VDD = 3.5V , V

VDD = 3.5V

OH =

VDD - 0.4V

V

VDD = 3.5V

OL =

V

0.4V

Distortion DIS% 1 5 % * see note below

* Note: DIS% =

1

1. V

. . . . Vn are the intermodulati on or t he harmonic frequencies in the 500Hz to 3400Hz band.

IL

and VIH are the individual frequency components of the DTMFsignal.

2. V

AC Characteristics

22 2

12 n

100*(V V ... V )

+++

22

IL IH

+

(V V )

(VDD = 3.5V, VSS = 0V, F

1/2

1/2

OSC

= 3.579MHz, Top = 25°C, unless otherwise specified.)

Parameter Symbol Min. Typ. Max. Unit Conditions

33.3

OL =

0.4V B

10pps

Test

KT.

B

B

M/B = 1/2

Make Time T

Break Time T

Inter-digit Pause Time T

Pause Time T

M

B

IDP

PAU

40.0

16.7

ms

20pps

M/B = 2/3

M/B = 1/2

20.0 M/B = 2/3

66.6

60.0

33.3

10pps

ms

20pps

M/B = 1/2

M/B = 2/3

M/B = 1/2

30.0 M/B = 2/3

824

ms

10pps

458 20pps

2.2 sec

4V1.0

AC Characteristics (co ntinued)

Parameter Symbol Min. Typ. Max. Unit Conditions

NT91214/15 Series

Auto-redial Break Tim e T

Delay time Key valid to Signal Out T

Key-in Debounce T

Key Release Debounce Tim e T

Key-in Tone Duration T

Key-in Tone Frequency F

Minimum Tone Duration Tim e T

Min. Tone Inter-digit Pause T

Redial Tone Duration T

Redial Tone Inter-digit Duration T

AOBK

D

KD

KLD

KTD

KT

MFD

TIDP

MFDR

TIDPR

2.2 sec * O ptional

0ms

21 ms

5.2 ms

23 ms

437 H

Z

94 ms

96 ms

94 ms

96 ms

Comparisons of Specified vs. Actual Tone Frequencies

R/C Spec. Actual Error (%) Unit Conditions

R1

R2

R3

R4

C1

C2

C3

697 699.1 +0.31 Hz

770 771.5 +0.19 Hz

852 852.3 +0.03 Hz

941 942.0 +0.10 Hz Fosc = 3.579MHz

1,209 1,215.7 +0.57 Hz

1,336 1,331.7 -0.32 Hz

1,477 1,471.9 -0.35 Hz

5V1.0

Pin Descrip t ions

NT91214/15 Series

Pin No.

NT91215A
NT91214A

3
4

2233MODE INI, ZTRI-STATE mode select pin

NT91215B

NT91214B

3
4

NT91215C
NT91214C

4
5

NT91215D
NT91214D

4
5

Designation I / O Description

OSCI

OSCO

I Oscillator Input and Output pins

The time base for the NT91214/15 is a
crystal controlled on-chip oscillator,
which is completed by connecting a

3.58MHz crystal or ceramic resonator
between the OSCI and OSCO pins.

There are two versions of the
NT91214/15 as follows:

a. NT91215 Series is for European and

American systems.

MODEINTone/

Pulse

VDD Pulse 10pps 2/3
VSS Tone - ­Floating Pulse 10pps 1/2

b. The NT91214 Series is for the

Japanese system.

MODEINTone/

Pulse

VDD Pulse 10pps 1/2

Dial

Rate

Dial

Rate

M/B

Ratio

M/B

Ratio

VSS Tone - ­Floating Pulse 20pps 1/2

The mode selection pin is checked for
tone/pulse dialing as each digit key
entery. In the PULSE mode, the dialing
rate is checked, along with the
make/break ratio, at first key entry.

6V1.0

Pin Descrip t ions (cont inued)

Pin No.

NT91214/15 Series

NT91215A
NT91214A

1122

(N.A.) 10 (N.A.) 11

9 111012

NT91215B

NT91214B

NT91215C
NT91214C

NT91215D
NT91214D

Designation I/O Description

HK

KT

DP

I Hook switch i nput

This inverter input pin detects the state
of the hook switch contact . "Off Hook" is
represented by a VSS
Hook" is represented by a VDD
condition.

O Key-in tone output

This N-channel open drain pin sends out
a "beep" tone for each PULSE mode key
entry, along with entries of accepted
function keys (RD, T, F1 F2, and P
keys). The tone output frequency is
437Hz and tone duration is 23 ms.

O Dial ing pulse output

This is an N-channel open drain output.
The normal output will be "ON" during
break and "OFF" during make in the
PULSE DIALING mode.

condition. "On

7V1.0