ELAN EM91455DK, EM91455CK, EM91455BP, EM91455AP Datasheet

GENERAL DESCRIPTION

The EM91455 is a series of tone/pulse switchable dialers that is composed of T/P dialer and T/P dialer with
3 sets memories. The EM91455 provide modern LCD driver's series data output port, which can display modern
function operating icons. The EM91455 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, ring detector and SDO (Serial Data
Output) functions are provided in advance version. 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 and
modern function operating icons can be displayed on LCD screen with LCD driver (EM32100 or EM32117 ).
The EM91455 has a special I.P.P. detect function (Illegal Parallel Phone Detect) can prevent the illegal connect
external Phone. The I.P.P. will detect the illegal user. When illegal user pickup phone, the function will alarm
and send the alarm signal to the telephone line to interfer the illegal dialing.

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

FEATURES

• I.P.P. detect function prevents the illegal connect external phone.

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

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

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

• Line hold function is designed for stopping conversation temporality.

• 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.

• 3-set one 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.

ORDERING INFORMATION

Versions list and function outline

VERSION LNB KT HOLD I.P.P. LOCK HF SDO(LCD) PDP
EM91455A √√√√√
EM91455B √√√√√√
EM91455C √√√√√√√
EM91455D √√√√√√√√
Note : PDP = Pocket Dialer Prevented

: I.P.P. detect = Illegal Parallel Phone Detect.

* This specification are subject to be changed without notice.

9.24.1998

1

EM91455

Pin Assignment

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

EM91455AP

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

EM91455CK

NC

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

HFI

10
11

EM91455BP

1

1

18

HDO

2

17

PO

3

16

ROW4

4

15

ROW3

5

14

ROW2

6

13

ROW1

7

12

HKS

8

11

VDD

9

10

DTMF

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

HFI

10

20

HDO

2

19

PO

3

18

ROW4

4

17

ROW3

5

16

ROW2

6

15

ROW1

7

14

HKS

8

13

VDD

9

12

DTMF

11

HFO

EM91455DK

NC

1

24

1

22

SDO

2

21

HDO

3

20

PO

4

19

ROW4

5

18

ROW3

6

17

ROW2

7

16

ROW1

8

15

HKS

9

14

VDD

13

DTMF

12

HFO

COL5

COL4/KT

COL3
COL2
COL1

XIN

XOUT

XMUTE

VSS

HFI

DRING

2
3
4
5
6
7
8

9
10
11
12

23
22
21
20
19
18
17
16
15
14
13

SDO
HDO
PO
ROW4
ROW3
ROW2
ROW1
HKS
VDD
DTMF
HFO
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

RD/P

COL5

EM1
EM2
EM3

ST

9.24.1998

2

FUNCTIONAL BLOCK DIAGRAM

COL1
COL2
COL3

COL4/KT

COL5

Keyboard

interface
(column)

SDO

HFO

HDO

Output circuit

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

RMUTE

Row/Column

programming counter

XMUTE

XIN

XOUT

ROW1

ROW4

I/O circuit

Oscillator

Timing/Control circuit

Keyboard

~

interface

(Row)

VDD

HFI

Memory

Input circuit

HKS

DRING

latch

&

decoder

Pulse

generator

D/A

converter

DTMF

PO

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 Input/Output structure pin. The output is a open drain structure. Input is schmitt trigger

structure. This pin will be input pin during ON-HOOK status for illegal parallel phone
detect input pin and will be output pin in OFF-HOOK condition for control speech
network.

VDD and V

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.

* This specification are subject to be changed without notice.

9.24.1998

3

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

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.

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.

9.24.1998

4

FUNCTION DESCRIPTIONS

Dialing signal selection

The EM91455 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

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

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.

9.24.1998

5

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

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 EM91455 series incorporated several sets repertory memory and each one can store number up to 16 digits.
These memories were designed to 3 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.

Storing of 3 sets memory

Direct (one-touch) operation

Off-hook (or turn on HF function), push (ST, d1, d2, .. , dn [ST], EMn The numbers d1, d2, .. , dn will be stored
into memory location “EMn”. The “EMn” expressed emergency memory EM1 to EM3.

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

Direct (one-touch) memory operation

• To select Pulse or Tone mode.

• Off-hook (or Turn on HF function), push “EMn” key. The numbers that are stored in direct memory location
“EMn” will be dialed out in Pulse or Tone mode as selection. The “n” expressed digital number from 1~3.

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.

9.24.1998

6

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

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 93 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 EM91455 series. To prevent the unavoidable long distance call, then EM91455 inhibits the key entry during
Tdly.

* This specification are subject to be changed without notice.

9.24.1998

7

EM91455 SERIES

TONE/PULSE DIALER WITH LCD INTERFACE

AND I.P.P. DETECT FUNCTION

Operating flow chart

HD

HD

HF

(4)

On-hook

Hand-free State

HF

(6)

On-hook

Hold-line State

HF

HKS=Hi

HKS=Lo

XMUTE

On-hook State

Hand-free State

HKS=Hi

=Hi

(1)

HKS=Lo

(3)

Off-hook

HF

HD

XMUTE=Lo

HKS=Lo

HKS=Hi

HF

HF

HF

(7)

IPP State

HKS=Lo

(2)

Off-hook State

HD

HD

(5)

Off-hook

Hold-line State

<Note> : HF = Handfree

HD = Hold

Truth table

Pin level

Operating state Input I/O Output

HKS XMUTE PO HFO HDO DTMF
(1) On-hook, idle state H H/F F L L ­(2) Off-hook line L H/F F L L ­(3) Off-hook, HF line L H/F F H L ­(4) On-hook, HF line H H/F F H L ­(5) Off-hook, HD line L L/L F L H ­(6) On-hook, HD line H L/L F L H ­(7) IPP state H L/L F H H active

Note : F=floating (high impedance); H=logic “High”; L=logic “Low” level.

XMUTE are I/O port, so Input will effect state situation change, and which state dialer stay will
effect output level.

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 EM32117
). The SDO signal consists of two start bits, six data bits and two stop bits. The 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

stop bits

1

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