NT91214/15 Series
Tone/Pulse Dialer
Features
T
One touch redial operation
T
Tone/Pulse switchable
T
32 digit capacity for redialing
T
Automatic mixed redialing (last number redial) of pulse
T
T
T
to DTMF with multiple automatic access pauses
PABX auto-pause is 2.2 seconds
DTMF Timing:
Manual dialing: minimum duration for bursts and
pauses
Redialing: calibrated timing
Hands-Free control function
T
Wide operating voltage range: 2V to 5.5V
T
Key-in beep tone output
T
Digits dialed manually after redialing are
T
T
T
T
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
DTMF mixed dialing
or
T
4 x 4 (or 2 x 8) keyboard can be used
T
Low standby current
General Description
The NT91214/15 is a single-chip, silicon gate, CMOS
integrated circuit with an on-chip oscillator for a 3.58MHz
crystal or ceramic resonator. It provides a dialing pulse
(DP) or dual tone multi-frequency (DTMF) dialing. A
standard 4 x 4 matrix 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
(i) Key Tone Output
c. 20-Pin Package
(ii) Hands-Free Control
1
V1.0
NT91214/15 Series
Keyboard Assignments
1
4
7
*/T
2
5
8
0
3
6
9
#
F1
F2
P
RD
R1
R2
R3
R4
C1
C2
C3
GND
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.
Block Diagram
2
V1.0
NT91214/15 Series
Absolute Maximum Ratings*
Supply Voltage (VDD). . . . . . . . . . . . . . . . . . . .≤ 6.0V
Input Voltage (V
IN
) . . . . . . .VSS - 0.3V to VDD + 0.3V
Output Voltage (V
OUT
) . . . . VSS - 0.3V to VDD + 0.3V
Output Voltage (V
OUT
)(
DP
,
XMIT MUTE
) . . . .
≤1.2V
Tone Output Current (I
TONE
) . . . . . . . . . . . . . .
≤50mA
Power Dissipation (P
D
) . . . . . . . . . . . . . . . . .
≤500mW
Operating Temperature (Top). . . . . . . -20°C to +70°C
Storage Temperature (Tstg). . . . . . . -40°C to +150°C
*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.
DC Electrical Characteristics
(VDD = 3.5V, VSS = 0V, Fosc = 3.579MHz, Top = 25°C)
Parameter
Symbol
Min.
2.0
2.0
Memory Retention Voltage
Memory Retention Current
V
MR
I
MR
I
DDP
I
DDT
1
0.05
0.32
0.6
0.03
0.4
1.0
2.0
0.05
µA
Typ.
Max.
5.5
5.5
V
µA
VDD = 1.0V,
HK
= VDD
All outputs unloaded
Pulse mode
Tone mode
HK
= VDD = 1.5V
Unit
Conditions
PULSE mode
TONE mode
Test
KT.
A
Operating Voltage
VDD
V
-
-
Operating Current
mA
All outputs
unloaded
A
Standby Current
Iso
0.5
V
IH
V
IL
R1
-
R4
Input Current
10
1
0.2
HK
= VSS
All outputs
unloaded,
no key
selected
A
Input Current
0.8
0
115
584
456
730
570
VDD
I
R
V
OC
V
OR
µA
876
684
µA
mVp-p
Column
Row
VDD = 3.5V
R
L
= 5K
C
D
Tone out Voltage
HFI
Pull Low Current
I
HFI
5
VDD = 3.5V (Note 1)
HFI
pin connected to 0V
B
3
V1.0
NT91214/15 Series
DC Electrical Characteristics (continued)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Conditions
VDD = 3.5V
V
OH =
VDD - 0.4V
VDD = 3.5V
V
OL =
0.4V
Test
KT.
B
HFO Drive Current
HFO,
KT
, MODEOUT
XMITMUTE
Sink Current
DP
Sink Current
I
OH1
0.4
2
mA
I
OL1
0.9
5.3
mA
B
I
OL2
DIS%
1.1
5.3
1
5
mA
%
VDD = 3.5V , V
OL =
0.4V
* see note below
B
Distortion
* Note:
DIS% =
100 * (V
1
2
+
V
2
2
+
...
+
V
n
2
)
1/2
(V
IL
2
+
V
IH
2
)
1/2
1. V
1
. . . . V
n
are the intermodulation or the harmonic frequencies in the 500Hz to 3400Hz band.
2. V
IL
and V
IH
are the individual frequency components of the DTMFsignal.
(VDD = 3.5V, VSS = 0V, F
OSC
= 3.579MHz, Top = 25°C, unless otherwise specified.)
Symbol
Min.
Typ.
33.3
Max.
Unit
Conditions
10pps
ms
20pps
M/B = 1/2
M/B = 2/3
M/B = 1/2
M/B = 2/3
10pps
ms
20pps
M/B = 1/2
M/B = 2/3
M/B = 1/2
M/B = 2/3
ms
10pps
20pps
sec
AC Characteristics
Parameter
Make Time
T
M
40.0
16.7
20.0
66.6
Break Time
T
B
60.0
33.3
30.0
Inter-digit Pause Time
T
IDP
824
458
Pause Time
T
PAU
2.2
4
V1.0
NT91214/15 Series
AC Characteristics (continued)
Parameter
Auto-redial Break Time
Delay time Key valid to Signal Out
Key-in Debounce
Key Release Debounce Time
Key-in Tone Duration
Key-in Tone Frequency
Minimum Tone Duration Time
Min. Tone Inter-digit Pause
Redial Tone Duration
Redial Tone Inter-digit Duration
Symbol
T
AOBK
T
D
T
KD
T
KLD
T
KTD
F
KT
T
MFD
T
TIDP
T
MFDR
T
TIDPR
Min.
Typ.
2.2
0
21
5.2
23
437
94
96
94
96
Max.
Unit
sec
ms
ms
ms
ms
H
Z
ms
ms
ms
ms
Conditions
* Optional
Comparisons of Specified vs. Actual Tone Frequencies
R/C
R1
R2
R3
R4
C1
C2
C3
Spec.
697
770
852
941
1,209
1,336
1,477
Actual
699.1
771.5
852.3
942.0
1,215.7
1,331.7
1,471.9
Error (%)
+0.31
+0.19
+0.03
+0.10
+0.57
-0.32
-0.35
Unit
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Conditions
Fosc = 3.579MHz
5
V1.0