TECHNICAL DATA
1
Tone/Pulse Dialer
High-Performance Silicon-Gate CMOS
The IN91210E is a single-chip, silicon gate, CMOS integrated circuit
with an on-chip oscillator for a 3.58 MHz crystal or ceramic resonator.
It provides dialing pulse (DP) or dual tone multi-frequency (DTMF)
dialing. A standard 4x4 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 reading. In the DTMF mode, minimum tone duration and
minimum intertone pause are provided for rapid dialing. Maximum
tone duration is dependent upon the key depression time in manual
dialing.
One touch redial operation
Tone/Pulse switchable
32-digit capacity for redialing
Automatic mixed redialing (last number redial) of pulse to DTMF
with multiple automatic access pauses
PABX auto-pause is 2.2 second
DTMF Timing:
Manual dialing: minimum duration for bursts and pauses
Redialing: calibrated timing
Wide operating voltage range: 2 V to 5.5 V
Digits dialed manually after redialing are cascadable and stored as additional digits for the next redialing
Uses inexpensive ceramic resonator (3.58 MHz)
Built-in power up reset circuit
Four extra function keys: flash, pause, redial and DP or DTMF mixed dialing
Four-by-four (or 2 of 8) keyboard can be used
Low standby current
Dial Pulse Rate: 10 pps
IN91210E
ORDERING INFORMATION
IN91210EN
T
A
= -20
to 70 C
PIN ASSIGNMENT
IN91210E
2
LOGIC DIAGRAM
PIN 11 = GND
PIN 10 = V
CC
Keyboard Assignments*
1
2
3
F1
R1
4
5
6
F2
R2
7
8
9
P
R3
*/T
0
#
RD
R4
C1
C2
C3
Internal Pull
Low
*Notes:
1. */T - At Pulse mode this key works as Pulse -> DTMF key (T key), at DTMF mode the key works as *key.
*/T key will occupy one memory digit in either mode.
2. F1 - Flash key. The break time is 96 ms.
3. F2 - Flash key for break time 640 ms.
4. P -- Pause key (2.2 seconds).
5. RD - One key redial key.
6. # - At pulse mode this key input is neglected, at DTMF mode this key works as # key.
IN91210E
3
Pin Description
Pin No.
Designation
Description
1
R1
2
R2
3
R3
4
R4
5
HK
Hook switch input.
This inverter input pin detects the state of the hook switch contact. "Off
Hook" is represented by a GND condition. "On Hook" is represented by a
V
CC
condition.
6
M/B
Make/Break Ratio Select Input.
This input allows selection of the Make/Break ratio.
M/B = V
CC
: 1/2
M/B = GND : 2/3
7
MODE SELECT
Mode select input.
This input allows the selection of pulse mode or DTMF mode.
MODE SELECT = V
CC
: Pulse mode operation
MODE SELECT = GND : Tone mode operation
8
9
OSCI
OSC0
Oscillator Input and Output pins.
The time base for IN91210E is a crystal controlled on-chip oscillator, which
is completed by connecting a 3.58 MHz crystal or ceramic resonator
between OSCI and OSC0 pins.
10
V
CC
11
GND
12
TONE
Tone dialing output.
When a valid keypress is detected in the DTMF mode, appropriate low
group and high group frequencies are generated, which hybridize the dual
tone output. TONE output is in the "OFF" state in pulse mode.
13
XMITMUTE
Dialing transmission mute output.
This is an N-channel open drain output
The XMIMUTE is normally "OFF". During pulse or DTMF dialing this
output is "ON".
14
DP
Dialing 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.
15
C1
16
C2
17
C3
18
C4
Internal Pull low.
Key board pins.
These inputs serve as the interface to a 4x4 matrix keyboard.
Key board pins.
These inputs serve as the interface to a 4x4 matrix keyboard.
Power supply pins.
This device is designed to operate from 2.0 V to 5.5 V.
IN91210E
4
Operation Procedures
Symbol Definitions:
In the description below, signals are defined in terms
of the key or switch which is activated.
Off Hook
means the phone was taken off the
hook.
On Hook
means that the receiver is onf the
hook.
D1
stands for the first digit dialed in a string
of digits.
Dn
stands for the last digit dialed in a string
of digits.
Dn+1
stands for the beginning of a new string
of digits.
Dn+m
stands for the last digit in a new string
of digits.
*/T
is the Pulse-to-DTMF key
RD
is the Redial key
O
is the Zero key.
P
is the Pause key.
F
is the Flash key.
1. Pulse mode operation
a.
Off Hook
D1
. . . . . .
Dn
Pulse mode is defined as the initial mode,
provided the first keyboard input is not the */T
key following the Off Hook condition and the
mode selection pin is V
CC
(MODE SELECT =
V
CC
).
b. Pulse mode is defined as the initial mode,
provided the key input D1 is not */T while the
mode selection pin is V
CC
. The chip will pause
for 824 ms automatically after it detects an
Off Hook condition. It then proceeds with pulse
or DTMF dialing if any keys have been
depressed. The dialing rate or make/break ratio is
decided at the first key entry by checking the
MODE SELECT & M/B status and will not be
altered. The MODE SELECT status can only
switch the dialing mode from Pulse to DTMF
after the first key entry.
2. DTMF mode operation
a.
Off Hook
D1
. . . . . .
Dn
DTMF mode is defined as the initial mode of the
mode selection pin if MODE SELECT is GND.
b.
Off Hook
*/T
D1
. . . . . .
Dn
The initial mode is pulse mode if the mode
selection pin, MODE SELECT, is V
CC
. The */T
key can switch the dialing mode to tone mode.
Unlike normal mode switching, the */T key entry,
as the first key pressed, will not produce any
pause time. There are only 31 digit of redial
memory available in the buffer to be used for
operations a and b, since the mode switching key,
*/T , will occupy one digit of space.
3. Manual dialing with automatic access pause
Off Hook
O
*/T
D1
. . . .
Dn
Pause key entries can be accepted and stored in
the redial memory. Each is stored as a digit. Each
key-in will provide a pause of 2.2 seconds,
depending on which model you are using.
4. Redial
a.
Off Hook
RD
Up to 32 digits (in pulse mode) or 31 digits (in
tone mode) can be dialed using the RD key. The
RD key is disabled while pulse or tone signals are
being transmitted. Redial will also be inhibited if
the last number dialed exceeds 32 digits because
the redial memory can only hold 32 digits.
b.
Off Hook
RD
D1
. . . . . .
Dn
After pressing the RD key, we can add digits to
the number in redial memory. When finished
dialing, the redial memory will contain the
original digits plus the digits dialed after pressing
RD. Each time the redial key is pressed, the
stored number will be dialed exactly the same as
it was previously, regardless of the status of the
MODE SELECT pin.
5. TONE/PULSE switching operation
a. Off Hook D1 . . . Dn MODE SELECT pin
Pulse Mode
switched to GND Dn+1 . . . . Dn+m
DTMF Mode
The mode selection pin is always checked for
tone or pulse mode key entry. Dialing can be
switched from pulse to tone mode, but not from
tone to pulse mode. Switching the
MODE SELECT pin to GND will cause the chip
to store a */T digit prior to the first tone digit in
the redial memory and will automatically insert a
2.2 second pause before the tone digits are dialed
out. After the mode has been switched, the status
of the mode selection pin will no longer be
checked. Therefore, it will not be possible to
switch from tone to pulse mode.
IN91210E
2
b. Off Hook D1 . . . Dn */T Dn+1
Pulse Mode
. . . . . . . Dn+m
DTMF Mode
Pulse mode is initially defined with the mode
selection pin, MODE SELECT, equal to V
CC
. At
this time, the mode can be switched to DTMF by
pressing the */T key. DTMF mode will begin as
soon as the last pulse has been transmitted. In this
mode, Dn+1 through Dn+m are sent through the
TONE OUT pin as DTMF signals. If a P key
entry is contained in the series of digits before or
after the */T entry, or the MODE SELECT switch
is depressed, 2.2 second pause will be added to
the automatically inserted pause time, which is
also 2.2 seconds. Both of the above switching
modes can store as many as 31 digits in the redial
memory.
6. One-Key redialing
Off Hook
D1
. . . . . .
Dn
RD
If the dialing of D1 to Dn is completed, pressing
RD will cause the pulse dialing pin to go low for
2.2 seconds of break time and an 824 ms pause
will automatically be added. Otherwise, the
pressing of the redial key will be ignored.
7. Flash dialing
Off Hook
F
D1
. . . . . .
Dn
The flash keys emulate quick On-Off Hook
operations. Pressing the flash keys, F1 or F2, will
cause a break of 96 ms or 640 ms on the DP
output pin. Then, it will pause for 824 ms and
continue dialing the digits, D1 to Dn . These
digits are then stored in the redial memory. Each
time the flash key is pressed, the redial memory
will be cleared to store a new entry. In addition,
the MODE SELECT status will be checked again
for the setting of the Tone/Pulse dialing mode.
Similarly, to make sure that the IC is working
properly, new flash key inputs will be ignored as
long as the digits that were dialed have not
finished.
MAXIMUM RATINGS
*
Symbol
Parameter
Value
Unit
V
CC
DC Supply Voltage (Referenced to GND)
-0.3 to +6.0
V
V
IN
DC Input Voltage (Referenced to GND)
-0.3 to V
CC
+0.3
V
V
OUT
DC Output Voltage (Referenced to GND)
-0.3 to V
CC
+0.3
V
V
OUT
DC Output Voltage (DP, XMITMUTE)
-0.3 to 1.2
V
I
TONE
DC Output Current(Tone)
50
mA
P
D
Power Dissipation in Still Air,
Plastic DIP
**
500
mW
Tstg
Storage Temperature
-40 to +125
C
*
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
**
Durating: -10
mW
/
C
from 65
C to 70C.
PDF 
ZIP