EM91220 SERIES
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
1
* This specification are subject to be changed without notice.
10.1.1997
GENERAL DESCRIPTION
The EM91220 is a series of tone/pulse switchable dialers that is composed of T/P dialer and T/P dialer with
20-set memories . The EM91220 series provides necessary functions of telephone set for application in any
environment, such as Pulse dialing, Tone (DTMF) dialing, Handfree dialing, keying tone , mute and pulse
mute functions. Beside this, SDO (Serial Data Output) functions is provided in advance version that is designed
to drive LCD driver and voice synthesizer. In this application, the dialing numbers can be displayed on LCD
screen with EM32100 ( or EM32116 ).
FEATURES
Tone/Pulse switchable.
Wide operating voltage from 2.0 V to 5.5 V.
Low operating current, 0.15 mA (Pulse) and 0.3 mA (Tone) typically.
Adding resistor on keyboard scan pin that can select many telephone specifications, such as : Pulse rate,
M/B ratio, Flash time, Pause time, P-T wait time and keyboard type.
SDO function supports LCD driver and voice synthesizer to indicate dialing numbers.
Handfree function provides on-hook dialing and speakerphone application.
20-set three touch repertory memory, each one can store data up to 16 digits.
A 32-digit LNB (last number) redial memory.
A 32-digit SAVE redial memory.
Keytone function provides rapidly keying recognition.
Pulse mute function supports pulse dialing application.
Using 3.579545 MHz crystal or ceramic resonator.
Package forms: PDIP, skinny.
ORDERING INFORMATION
Versions list
VERSION LNB KT SAVE HF SDO(LCD) PMUTE
EM91220A
EM91220B
EM91220C
EM91220 SERIES
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
EM91220 SERIES
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
2
* This specification are subject to be changed without notice.
10.1.1997
FUNCTIONAL BLOCK DIAGRAM
EM91220
Pin Assignment
Keyboard Arrangement
Type A
Type B
COL5
COL4/KT
COL3
COL2
COL1
XIN
XOUT
XMUTE
VSS
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
PM
PO
ROW4
ROW3
ROW2
ROW1
HKS
VDD
DTMF
EM91220AP
COL5
COL4/KT
COL3
COL2
COL1
XIN
XOUT
XMUTE
VSS
HFI
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
PM
PO
ROW4
ROW3
ROW2
ROW1
HKS
VDD
DTMF
HFO
EM91220BP
NC
COL5
COL4/KT
COL3
COL2
COL1
XIN
XOUT
XMUTE
VSS
HFI
1
2
3
4
5
6
7
8
9
10
11
22
21
20
19
18
17
16
15
14
13
12
SDO
PM
PO
ROW4
ROW3
ROW2
ROW1
HKS
VDD
DTMF
HFO
EM91220CK
ROW1
ROW2
ROW3
ROW4
COL1
1
4
7
*/T
COL2
2
5
8
0
COL3
3
6
9
#
COL4/KT
SAVE
F
A
RD/P
COL5
ST
ROW1
ROW2
ROW3
ROW4
COL1
1
4
7
*
COL2
2
5
8
0
COL3
3
6
9
#
COL4/KT
SAVE
F
A
RD/P
COL5
P
T
ST
COL1
COL2
COL3
COL4/KT
COL5
XIN
XOUT
ROW1
ROW4
HFO PM
XMUTE
Keyboard
interface
(column)
Oscillator
Keyboard
interface
(Row)
Output circuit
Memory
(Melody)
Timing/Control circuit
Input circuit
Pulse
generator
latch
&
decoder
D/A
converter
Row/Column
programming counter
DTMF
PO
HKS
HFI
VDD
VDD
SDO
~
EM91220 SERIES
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
3
* This specification are subject to be changed without notice.
10.1.1997
PIN DESCRIPTIONS
Symbol
Function
ROW1~ROW4
Keyboard scan pins of row group. In idle state (HKS is "High" and HFO is "Low"),
these pins stay "High impedance" level to prevent power consumption. Otherwise,
these pins switch to "High" level for detecting keyboard entry. These pins will output
600 Hz signal while keyboard is scanning.
COL1~COL3 and COL5
Keyboard scan pins of column group. In idle state, these pins stay "High impedance"
level. Otherwise these pins switch to "Low" level for detecting keyboard entry. These
pins will output 600 Hz signal while keyboard is scanning.
COL4/KT
The fourth column group pin of the keyboard that also provides the keytone output
. Normally, this pin stays "Low" level for detecting keyboard entry. After a valid
keyboard entry, this pin will output keying confirmation tone that is 600 Hz signal and
30 ms duration. While DTMF output, the key tone will be disabled. To prevent signal
interference, while DTMF issue, it will disable key tone output except function key.
XIN and XOUT
Oscillator input and output pins. A 3.579545 MHz crystal or ceramic resonator must
be crossed connection to XIN and XOUT pins which generate system clock.
XMUTE
The Tone/Pulse MUTE signal output pin that is NMOS open-drain output structure.
This pin will switch to "Low" level during Tone/Pulse dialing.
Otherwise, this pin stays "High impedance" level.
V
DD
and V
SS
Positive and negative power supply input pins. Recommended operating voltage from
2.0Vdc to 5.5Vdc.
HFI
Handfree inputs pin which accepts falling edge signal to turn "on" or turn "off"
handfree function. This pin is hysteresis input structure and built-in pull up resistor
(typically 200 Kohms).
HFO
Handfree outputs pin that is designed to control telephone line for on-hook dialing or
control speakerphone circuit for handfree conversation. When handfree function is
executed, this pin will switch to"High". Otherwise, this pin stays "Low" level.
DTMF
The DTMF (Dual Tone Multi-Frequency) output pin. Normally, this pin stays"Low"
level. In Tone dialing mode, this pin will output DTMF signal that is corresponding
to keyboard 0..9, * and # keys.
HKS
Control signal inputs pin that is corresponding hook switch status. When handset was
left from cradle, this pin must be connected to "Low" level to operate all functions.
Otherwise, this pin must be connected to "High" level to disable all function and
prevent power consumption.
PO
Pulse signal outputs pin that is NMOS open-drain output structure. Normally, this pin
stays "High impedance" level. In Pulse dialing mode and keypad was entry. This pin
will output pulse trains signal that is corresponding to keyboard 0 .. 9 keys.
PM
Pulse signal outputs pin that is CMOS inverter output structure. Normally, this pin
stays "Low" level. During pulse signal dialing or flash function executing, this pin will
switch to "High" level to control the external circuit.
SDO
SDO function output that is NMOS open-drain structure. When there is a valid entry
on keyboard, this pin will output a serial data. This serial data is designed to drive LCD
driver to display dialing number on LCD screen or drive voice synthesizer to announce
dialing number to speaker.
NC
No connection.
EM91220 SERIES
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
4
* This specification are subject to be changed without notice.
10.1.1997
FUNCTION DESCRIPTIONS
Dialing signal selection
The EM91220 series incorporated a special keyboard scanning function that is connecting a resistor (typically
is 560 Kohms) on keyboard scan pin to select many telephone specifications. The specifications are described
as following :
a. Mode
b. M/B ratio
ROW1
Mode
ROW2
MBR (%)
R-Vdd
20 PPS
NR
40:60
NR
Tone
R-Vss
33:66
R-Vss
10 PPS
c. Flash time
d. DTMF signal
ROW3
ROW4
Tf (ms)
COL1
Td (ms)
Titp (ms)
NR
NR
600
R-Vdd
90
90
NR
R-Vss
100
NR
98
98
R-Vss
NR
80
R-Vss
83
83
R-Vss
R-Vss
300
e. Pause time and P-T wait time
f. Keyboard operate type
COL2
Tp (sec)
Tpt (ms)
COL3
Type
NR
3.6
3.6
NR
A
R-Vss
2.0
2.0
R-Vss
B
Normal dialing
Directly keying digital key on keyboard which number can be dialing output and stored in LNB memory
automatically. Operating procedure described as follow :
To select Pulse or Tone mode.
Off-hook or turn on HF function.
Keying d1, d2, .. , dn. The "d" expressed digital keypad that included 1~9, *, 0, #, P, and P
T keys. The "n"
expressed unlimited.
The numbers d1, d2, .. , dn will be dialed out in Pulse or Tone mode as selection.
LNB redial memory
Storing:
In normal dialing mode, every digital key was entry which number will be stored in LNB memory
automatically. If entry digits are more than 32 digits, the redial function of LNB memory will be disabled.
Otherwise, these numbers stored in LNB memory can be redial output.
Redialing:
After normal dialing, directly keying F key (or On-Off hook once) and keying RD key on keyboard. The
numbers that are stored into LNB memory will be dialed output.
SAVE redial memory
The SAVE meomry is designed in EM91220 series to support 32 digits capacity buffer for second redial,
pager, Memory and other system applications.
EM91220 SERIES
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
5
* This specification are subject to be changed without notice.
10.1.1997
Method 1
To select Pulse or Tone mode.
Off-hook (or turn on HF function), push d1, d2, .. , dn. The numbers d1, d2, .. , dn will be dialed out in Pulse
or Tone mode as selection.
After dn had been dialed out and push [ST], Save key. If the keying numbers are more than 32 digits that
content of SAVE memory can not be updated. Otherwise, these numbers will be stored into SAVE memory.
In the [] key allows to be omitted.
Method 2
Off-hook (or turn on HF function), push ST, d1, d2, .. , dn, [ST], Save. If the keying numbers are not over 32
digits, the numbers d1, d2, .. , dn will be stored in SAVE redial memory automatically.
Dialing :
To select Pulse or Tone mode.
Off-hook (or turn on HF function), push Save key. The numbers stored in SAVE memory will be dialed out
in Pulse or Tone mode as selection.
Repertory memory
The EM91220 series incorporated several sets repertory memory and each one can store number up to 16 digits.
In memory storing, if stored numbers are more than 16 digits that only the previous 16 digits can be stored into
specific memory. Otherwise, these numbers can be stored entirely. After memory dialed out, the content of
LNB is keeping to current data.
Storing of 20 sets memory types
Indirect (three-touch) operation
Off-hook (or turn on HF function), push ST, d1, d2, .. , dn, ST, n, n. The numbers d1, d2, .. , dn will be stored
into memory location "n n". The "n n" expressed digital number from 01 to 20.
Dialing (after memory dialed out, the content of LNB is keeping to current data)
Indirect (three-touch) memory types
To select Pulse or Tone mode.
Off-hook (or Turn on HF function), push A, n , n key. The numbers that are stored in indirect memory
location "n n" will be dialed out in Pulse or Tone mode as selection . The "n n" expressed digital number
from 01 to 20.
Pause (P) key operation
The Pause (P) key is designed to support pause operation in dialing duration. "P" key can be stored in memory
and it will occupy one digital position.
To select Pulse or Tone mode.
Off-hook (or turn on HF function), push d1, d2, .. , dn, RD/P, k1, k2, .. , kn . These numbers will be dialed
out as following sequence:
d1, d2, .. , dn, Tp, k1, k2, .. , kn.
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