ELAN EM91440DK, EM91440CK, EM91440BP, EM91440AP Datasheet

GENERAL DESCRIPTION

The EM91440 is a series of tone/pulse switchable dialers that is composed of T/P dialer and T/P dialer with
40-set memories. The EM91440 series provide necessary functions of telephone set for application in any
environment, such as Pulse dialing, Tone (DTMF) dialing, Handfree dialing, keying tone ,and lock functions.
The lock function is designed to inhibit toll dialing operation. Beside this, melody generator, ring detector and
SDO (Serial Data Output) functions are provided in advance version. Melody generator will output dual-tone
music in line hold duration. Ring detector can prevent illegal dialing from pocket dialer. The SDO 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, lock dialing functions.

•SDO function supports LCD driver and voice synthesizer to indicate dialing numbers.

•Line hold function is designed for stopping conversation temporality.

•Melody generator provides music on hold function.

•Lock function provides conventionality key lock and password lock operations.

•Ring detector is designed to prevent illegal dialing from pocket dialer.

•40-set three touch repertory memory, each one can hold data up to 16 digits.

•A 32-digit LNB (last number) redial memory.

•Keytone function provides rapidly keying recognition.

•Handfree function provides on-hook dialing and speakerphone application.

•Pause and P-T time are fixed to 3.6 seconds.

•Tone duration and inter-tone pause time are fixed to 98 ms.

•Using 3.579545 MHz crystal or ceramic resonator.

•Package forms: PDIP, skinny.

EM91440 SERIES

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

AND DUAL-TONE MELODY GENERATOR

ORDERING INFORMATION

Versions list and function outline

VERSION LNB KT HOLD(music) LOCK HF SDO(LCD) PDP
EM91440A √√√ √
EM91440B √√√ √√
EM91440C √√√ √√√
EM91440D √√√ √√√√
Note : PDP = Pocket Dialer Prevented

* This specification are subject to be changed without notice.

10.1.1997

1

EM91440

Pin Assignment

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

EM91440AP

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

EM91440CK

NC

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

HFI

EM91440BP

20

18

1
2
3
4
5
6
7
8
9

HDO

17

PO

16

ROW4

15

ROW3

14

ROW2

13

ROW1

12

HKS

11

VDD

10

DTMF

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

HFI

1
2
3
4
5
6
7
8
9

10

HDO

19

PO

18

ROW4

17

ROW3

16

ROW2

15

ROW1

14

HKS

13

VDD

12

DTMF

11

HFO

EM91440DK

SDO

22

1

HDO

21

2

PO

20

3

ROW4

19

4

ROW3

18

5

ROW2

17

6

ROW1

16

7

HKS

15

8

VDD

14

9

DTMF

13

10

HFO

12

11

NC

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

HFI

DRING

24

1
2
3
4
5
6
7
8

9
10
11
12

SDO

23

HDO

22

PO

21

ROW4

20

ROW3

19

ROW2

18

ROW1

17

HKS

16

VDD

15

DTMF

14

HFO

13

RMUTE

Keyboard Arrangement

ROW1
ROW2
ROW3
ROW4

COL1

1
4
7

*/T

COL2

2
5
8
0

* This specification are subject to be changed without notice.

COL3

3
6
9
#

COL4/KT

HD

F
A

RD/P

COL5

ST

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FUNCTIONAL BLOCK DIAGRAM

COL1
COL2
COL3

COL4/KT

COL5

XIN

XOUT

Keyboard

interface

(column)

Oscillator

SDO

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

RMUTE

HFO

HDO

Output circuit

Memory

(Melody)

XMUTE

latch

decoder

Row/Column

programming counter

&

D/A

converter

DTMF

VDD

Timing/Control circuit

Input circuit

DRING

HKS HFI

generator

VDD

Pulse

PO

ROW1
ROW2
ROW3
ROW4

Keyboard

interface

(Row)

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. 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 and hold function .
Otherwise, this pin stays “High impedance” level.

V

and V

DD

SS

HFI Handfree inputs pin which accepts falling edge signal to turn “on” or turn “off”

HFO Handfree outputs pin that is designed to control telephone line for on-hook dialing or

DTMF The DTMF (Dual Tone Multi-Frequency) and music signals output pin. Normally,

Positive and negative power supply input pins. Recommended operating voltage from

2.0Vdc to 5.5Vdc.

handfree function. This pin is hysteresis input structure and built-in pull up resistor
(typically 200 Kohms).

control speakerphone circuit for handfree conversation. When handfree function is
executed, this pin will switch to“High”. Otherwise, this pin stays “Low” level.

this pin stays “Low” level. In Tone dialing mode, this pin will output DTMF signal
that is corresponding to keyboard 0 .. 9, * and # keys. Beside this, in the line hold
duration, this pin will issue dual-tone music for telephone line.

* This specification are subject to be changed without notice.

10.1.1997

3

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

Symbol Function

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.

HDO Hold function output that is CMOS structure.Normally, this pin stays “Low” level.

When Hold function is executing, this pin will output “High” level. This pin is
designed to drive LED or peripheral circuit to indicate line is at Hold status.

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.

DRING The ring signal detect input pin which is internal pull up (built-in 100 Kohms resistor).

While the Tel-ring is incoming, this pin must be connected to “Low” with delay to
indicate the ringing . Otherwise, this pin must be connected to “High” level .

RMUTE Ring mute output pin that is NMOS open-drain structure. The RMUTE pin is

designed to control microphone of handset to prevent the illegal dialing from pocket
dialer. If the DRING pin is at “High” level , then Off-Hook or turn on Handfree , this
pin will output “Low” level. In other words, the DRING pin is used to check the phone
that receives an incoming call (DRING =Low input) or make an outgoing call
(DRING= High input) . If the phone user make an outgoing call ,then RMUTE pin
activated to prevent the illegal dialing from pocket dialer in the particular application.The
RMUTE can be restored to “High” level when the first key entry is not the optioned
lock-number .

NC No connection.

* This specification are subject to be changed without notice.

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FUNCTION DESCRIPTIONS

Dialing signal selection

The EM91440 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. Lock control method

ROW3 ROW4 Tf (ms) COL1 Control method

NR NR 600 R-Vdd key lock

NR R-Vss 100 NR none lock
R-Vss NR 80 R-Vss password lock
R-Vss R-Vss 300

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

e. Lock number

COL2 COL3 Lock number

NR NR none

NR R-Vss 0
R-Vss NR 9
R-Vss R-Vss 0.9

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.

* This specification are subject to be changed without notice.

10.1.1997

5

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

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.

Repertory memory

The EM91440 series incorporated several sets repertory memory and each one can store number up to 16 digits.
These memories were designed to 40 sets types. 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.

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 40.

Dialing (after memory dialed out, the content of LNB is keeping to current data)

Indirect (three-touch) memory

• 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 40.

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.

Pulse to Tone (*/T) key operation

The Pulse to Tone (*/T) key is designed to support toll dialing (long distance call) or PABX system operation.
The “*/T” key can be stored in memory and it will occupy one digital position.

• To select Pulse mode.

• Off-hook (or turn on HF function), push d1, d2, .. , dn, */T, k1, k2, .. , kn. These numbers will be dialed out
as following sequence:

d1, d2, .. , dn, Tpt, k1, k2, .. , kn.

(pulse mode) (tone mode)

* This specification are subject to be changed without notice.

10.1.1997

6

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

Flash (F) key operation

The Flash (F) key is designed to break telephone line temporarily. After F key is depressed, this dialer will send
a flash signal to break line 600 ms, 300 ms, 100 ms or 80 ms; as ROW3 and ROW4 selection.

Handfree (HF) function

The handfree function is designed to support on-hook dialing and loudspeaker application which can be turn “on”
or “off” with falling edge signal from HFI pin. During handfree function is executed, the HFO pin is switched
to “high”. Otherwise the HFO pin stays “low” level. One of the following operations can turn off Handfree
function (HFO pin return to “Low”).

• On-off hook once.

• Trigger HFI pin with falling edge signal.

• Turn on Hold (HD) function. (HDO pin switched to “High”)

Hold (HD) function

The Hold function is designed to stop conversation temporarily. In off-hook state (or HF function is turned on),
to press HD key on the keyboard, the Hold function can be turned “on” (HDO pin switched to “High”). One of
the following operations can turn off Hold function (HDO pin switched to “Low”).

• On-off hook once.

•To press HD key over 280 ms.

• Turn on Handfree (HF) function. (HFO pin switched to “High”)

Special Note:

A 300 ms delay time (Tdly) at the first Off-Hook or turn on Handfree that is a special designed to avoid a rapid
key entry (dummy number ) in this time duration ,and a long distance call number follows. For example,

Off-Hook , “3” ,............ , “0” ,1,2,3......

Dummy key Lock number key
The dummy number “3” is not detected by the centered office or PABX ,but the following numbers “0” ,1,2,3...
long distance call can be dialed out normally since the leading number “3” is not the Lock-number defined in
EM91440 series. To prevent the unavoidable long distance call, then EM91440 inhibits the key entry during
Tdly.

* This specification are subject to be changed without notice.

10.1.1997

7

Operating flow chart

HF

EM91440 SERIES

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE

AND DUAL-TONE MELODY GENERATOR

HKS=Lo

1

On-hook State

HF

HKS=Hi

2

Off-hook State

HD

5

Off-hook

HD

4

On-hook

Hand-free State

HD

Hold-line State

HF

6

On-hook

HKS=Hi

HKS=Lo

3

Off-hook

Hand-free State

HD

HKS=Hi

HKS=Lo

HF

HF

HF

Hold-line State

<Note> : HF = Handfree

HD = Hold

Truth table

Operating state Input/Output pin level

HKS PO XMUTE HFO HDO
(0) On-hook, idle state H F F L L
(1) Off-hook line L F F L L

(2) Off-hook, HF line L F F H L
(3) On-hook, HF line H F F H L
(4) Off-hook, HD line L F L L H
(5) On-hook, HD line H F L L H
Note : F=floating (high impedance); H=logic “High”; L=logic “Low” level.

HD

Music on Hold

EM91440 series built-in a melody generator to generate dual-tone music on DTMF output pin. The music is
designed for telephone line at line holding.

SDO (Serial Data Output) function

The SDO is serial data output which format is same as UART protocol. SDO function is designed to drive LCD
driver and voice synthesizer. So the dialing numbers can be display on LCD screen with EM32100 (or EM32116
). The SDO signal consists of two start bits, six data bits and two stop bits. Each bit time is about 3.9 ms (256 Hz)

and output sequences are following by start bits, data bits (LSB to MSB) and stop bits.

ready

0

start bits

1 bit 0

bit1

* This specification are subject to be changed without notice.

bit2 bit3 bit4 bit5
data bits

0

1

stop bits

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