XECOM XE1414B Datasheet

XECOM (1) XE1414B

Low-Cost, Embeddable 14,400 BPS Modem Module

XE1414B

June 2000

Block Diagram

Modem

Controller

ROM

NVRAM

Analog

Front

End

DAA

/DTR

/RTS
/CTS
/DSR
TXD
RXD

/DCD

Serial I/O

RESET

AR

OH

AMP

Tip

Ring

Auxiliary I/O

Description

Xecom's XE1414B is a complete, low-cost 14,400 bps
modem in a single component. The XE1414B includes
traansferrable FCC part 68 Registration and is a UL1950
recognized component.

The XE1414B is a complete modem and includes the
DAA. XE1414B users do not need to add RAM, ROM,
Crystals, transformers, or switches to complete the
modem design. The user only needs to provide the TTL
level, serial interface and the telephone jack.

The XE1414B is a full-featured modem. Besides 14.4
Kbps data transfer, the XE1414B supports data compres­sion, error correction and fax transfer. The XE1414B
also includes NVRAM for permanent storage of the
modem configuration.

The XE1414B is pin compatible with Xecom's XE3314B
modem. This family of modems permits a simple
upgrade path from 14400 bps to 33,600 bps.

Features

*

FCC Part 68 Registration transferrable to customer’s

system.

* UL1950 Recognized Component

*

Small Size: 2.75 inches by 1.38" by 0.42"

* Modem Control and Configuration through industry

standard AT Commands

*

Modem Protocols: V.34bis, V.34, V.32bis, V.32,

V.22bis, V.22, V.21, Bell 212A and 103

*

Fax Protocols: V.17, V.29, V.27ter, and V.21 channel 2

*

Error Correction; V.42, MNP2-4 and MNP10

*

Data Compression; V.42bis and MNP5 provides a

maximum effective data rate of 133,400 bps.

*

Pin compatible with Xecom's XE1414C, XE3314B,

XE3314C and XE5614C modems.

XECOM (2) XE1414B

XE1414B Mechanical Specifications

A

B

Denotes Pin 1

C

D

G

J

H

E

F

K

Pins = 0.025 inch square pin
All pins tin-plated

XE1414B PIN CONFIGURATION

NC
AR

RXD

NC
NC
NC
NC

NC
/DTR
TST3

/CTS

NC

TXD

/RTS

NC

/RI

TIP

RING

VCC
/DSR
/DCD
NC
RESET
NC
NC
NC
NC
NC
OH
NC
TST1
TST2

AMP
GND

1
2
3

4
5
6
7
8

9
10
11
12
13
14
15
16

18

20

40
39
38
37
36
35
34
33

32

31
30
29
28
27

22
21

A 2.74 2.760 69.60 70.10
B 1.370 1.390 34.80 35.31
C 0.420 0.430 10.67 10.92
D 1.190 1.210 30.23 30.73
E 1.890 1.910 48.01 48.51
F 0.125 0.200 3.18 5.08
G 0.080 0.100 2.03 2.54
H 0.415 0.435 10.54 11.05
J 0.090 0.110 2.29 2.79
K 0.020 0.025 0.51 0.64

INCHES METRIC(MM)

PIN MIN MAX MIN MAX

XECOM (3) XE1414B

PIN NAME DESCRIPTION

XE1414B Pin Descriptions

1 NC No Internal Connection
2 AR Auxiliary Data/Voice Relay, Active High Output, TTL/CMOS. The AR signal goes high when ever

the modem is in the on-hook state. It can be connected to an external relay to switch control of the
telephone line between the modem and an auxiliary handset when.

3 RXD Received Data, Output, TTL. Serial data output to the host. A logic "High" on RXD represents a

"mark" and a logic "Low" represents a "space".

4-8 NC No Internal Connection

9 \DTR Data Terminal Ready, Output, active Low, TTL. The "AT&D" command sets the function of DTR.

The default, AT&D2, requires the host to assert DTR to permit a modem link. The modem drops the

call in progress if DTR is revoked and will not connect until DTR is re-asserted.
10 TST3 Test 3 is used for manufacturing test only. It has no function in normal operation.
11 \CTS Clear to Send, Output, active Low, TTL/CMOS. CTS is used as a Flow Control output from the

modem. The modem revokes CTS with hardware flow control active to signal the host that the

modem's input buffer is full. The modem reasserts CTS when the buffer can accept more data without

a buffer overflow.
12 NC No Internal Connection
13 TXD Transmit Data, Input, TTL. Serial data input from the host. A logic "High" represents a "mark" and a

Low represents a"space", TTL.
14 \RTS Request to Send, input, active LOW, TTL. The XE1414B uses RTS for hardware flow control. When

RTS is revoked; hardware flow control is enabled, and the modem will not place data on RXD.
15 NC No Internal Connection
16 \RI Ring Indicator, Output, active Low, TTL. When low indicates the modem is receiving a ring signal.
18 TIP Tip connection to the phone line(RJ11 pin3) from the internal DAA. The XE1414B is not sensitive to

the battery voltage polarity across Tip and Ring.
20 RING Ring connection to the phone line(RJ11 pin4) from the internal DAA.
21 GND Ground (0 volts)
22 AMP Audio Output function is set by L & M commands and the value in register S22. This output can drive

a minimum load of 300 ohms.

27, 28 TST1, TST2 Test 1 and Test 2 are used for manufacturing test only. They have no function in normal use. These

pins connected to the telephone line side of the telephone interface circuit so isolation must be

maintained between these signals and all other circuits.
30 OH Off-Hook, Output, active High. OH indicates the modem's hookswitch relay is closed. Hookswitch

closure connects the modem to the telephone line. This signal is available only on the XE1414B.
36 RESET Hardware reset pin, Input, active High, TTL. A high on Pin 1 initiates a hardware reset. An external

reset is not required or recommended. The Reset pulse must be a minimum of 100 milliseconds long.
38 \DCD Data Carrier Detect, Output, active Low, TTL/CMOS. &C sets the DCD function. In the default

condition, AT&C1, DCD indicates the presence of a carrier signal on the telephone line.
39 \DSR Data Set Ready, Output, active Low, TTL/CMOS. &S sets the DSR function. In the default condition,

AT&S0, DSR is forced true.
40 Vcc +5 Volts

XECOM (4) XE1414B

XE1414B ELECTRICAL SPECIFICATIONS

VCC 4.75 5.25 Volts
ICC 120 1 50 17 0 mamps On Line
Ring Voltage Detected 38 150 RMS XE1414B
Ring Frequency Detected 15.3 68 Hz
Telephone Loop Current 10 100 mamps XE1414B
Data Transmit level -12 -10.5 -9.0 dBm
DTMF Transmit Level -2.5 0 dBm Avg over 3 second interval

Parameter Min Typ Max Units Comments

ABSOLUTE MAXIMUM RATINGS*

SUPPLY VOLTAGE - Vcc +6.5 Volts

DC INPUT VOLTAGE -0.6 Volts to +6.5 Volts

STORAGE TEMPERATURE RANGE -25° C TO +85° C

LEAD TEMPERATURE (Soldering, 2 sec per wave) 260° C

OPERATING TEMPERATURE RANGE 0 TO 70° C

*Exceeding these values may result in permanent damage to the device.

XECOM (5) XE1414B

XE1414B Typical Applications Schematic for US, Canada and Japan

Tip
Ring

L1

L2

C1

C2

J1

VCC

TXD

RXD

+5 Volts

50K

.2 ufd

250 ufd

.05 ufd

10 ohms

8 ohm .5 W
Speaker

AMP

4 3

Line

GND

LM386

/RI

/RTS

/CTS

/DTR

/DSR

/DCD

16C450

UART

/DSR

/DCD

SIN

/DTR

/CTS

SOUT
/RTS

/RI

XE3301

Note: RJ11 Pin assignments reflect a 6-pin connector. Tip and Ring are always the center pins of the RJ11 jack.

Recommended Parts

Reference Designation Description Recommended Part Number

L1, L2 Ferrite Beads TDK ACB2012L-120-X
C1, C2 Capacitors Panasonic ECKDRS471, 470 pfd, 2600 Volts

J1 RJ11 Jack Stewart SS6446NF

XE1414B

XECOM (6) XE1414B

XE1414B AT Commands

Modes of Operation

The XE1414B uses "AT" commands for control and
configuration. The XE1414B operates in three modes;
Command Mode, Fax Mode and Data Mode. Exten­sions to the AT command set support fax operation.

Data Mode: The modem enters data mode after it es­tablishes a link and issues a "CONNECT" result code.
In Data Mode the modem modulates all signals on
Transmit Data, Pin 13, and sends them to the remote
modem. The modem demodulates the signal from the
remote modem and places it onto Received Data, Pin 3,
for the host equipment. When the modem exits data
mode, it issues a "NO CARRIER" result code.

Command Mode: The XE1414B enters command
mode on application of power, reset, loss of the con­nection, or receipt of the escape sequence. In com­mand mode the modem accepts commands from the
host on Transmit Data. Appropriate result codes are re­turned on Received Data at the same speed and parity
as the commands.

Fax Mode: The modem enters fax mode on receipt of
the AT+FCLASS=1 command. Fax commands and re­sponses are issued at 19,200 bits per second; the char­acter format is 8 bits no parity. The modem accepts
Class 1 Fax commands only in fax mode. The A/,
ATO, AT&T and escape commands are not valid in fax
mode.

Commands

The modem is configured and controlled with AT com­mands. AT commands follow a strict format. The
command line is stored in the command buffer and ex­ecuted upon receipt of a carriage return. Until ex­ecuted, the command line can be edited with the back­space key.

Command Format - Each command, except A/, begins
with the AT prefix. The "A" and "T" may be both up­per case or both lower case but cannot be of different
cases. The modem uses the prefix to identify the host's
speed and parity. The modem determines speed by
measuring the width of the incoming bits and parity by
comparing the parity bits of the "A" and "T." The mo­dem then returns result codes at the host's speed and
parity.

Command Line - A command line may include mul­tiple commands. The modem executes the commands
in the sequence they appear in the command line.
Spaces, inserted to improve legibility, do not fill space
in the command buffer. A carriage return terminates the
command line and causes the commands to be ex­ecuted. Register S3 allows the user to select a character
other than a carriage return to terminate the command
line.

Command Buffer - The command buffer holds 40
characters, including the AT prefix. If it overflows, the
modem issues an "ERROR" result code and commands
are not executed.

Command Line Editing - A backspace can be used to
edit the command any time before it is executed. The
backspace character, Control and H simultaneously on
some systems, erases the previous character in the
command line. Any character except for the "A" and
"T" can be erased. Register S5 allows the user to se­lect a character other than a backspace to edit the com­mand line.

Re-Execute Last Command - The A/ command
causes the modem to re-execute the command line
stored in the command buffer. This is the only com­mand which does not require the "AT" prefix.

Omitted Parameters - Most commands include a pa­rameter which determines the command function.
When the parameter is omitted from the command
string, it is assumed to be a 0.

Escape Characters - A three character escape se­quence, entered while in data mode, will switch the mo­dem into command mode while remaining on line. The
escape character, set by Register S2, is entered 3 times
in succession to execute the escape. The default es­cape sequence is "+++."

Result Codes - The modem issues a result code after
each action. Result codes may be provided as full
words, numeric codes or may be disabled. Each result
code ends with a carriage return when numeric result
codes are chosen. When full word result codes are cho­sen, a Line Feed and Carriage Return precede and fol­low each result code.