Modular DAA with 2/4 Wire Convertor
The XE0002D is a compact DAA module designed
Small Size: just 1.25 inches by 1.0 inches by
for applications requiring voice, data or fax
0.32 inches high
transfer. It complies with FCC Part 68 rules for
FCC Part 68 Compliant
direct connection to the public switched telephone
network and also supports leased line applications.
User selectable 2-4 wire convertor
Active Low Ring Detection
The XE0002D provides a complete telephone
Integral Switch Hook
interface. It includes the 2/4 wire convertor to
separate transmit and receive signals, ring
Supports V.32 Data Transfer
detection, integral switch hook and telephone line
Supports both dial-up and leased line
transformer. All of this circuitry is integrated into a
module requiring only 1.25 inches of board space.
Extended Operating Temperature Range (-40C
to +85C) available
XE0002D Block Diagram
Hook - Switch
2/4 - Wire
Jumpers J1 and J2 must be installed to connect the 2 to 4 wire convertor.
XE0002D Mechanical Specifications
XE0002D Pin Configuration
XE0002D Pin Descriptions
VDD supplies -5 Volt power to the XE0002D’s 2 to 4 wire converter.
VCC supplies +5 Volts power to the XE0002D
Ring Indicate, output, active low, TTL. /RI indicates the XE0002D is receiving a ring
signal. /RI remains low for the duration of each ring.
RCVR acts as the analog output from the XE0002D’s 2 to 4 wire converter. Signals
pass from the telephone line to the host via RCVR
XMIT provides the analog input to the XE0002D’s 2 to 4 wire converter. Signals
placed on XMIT are sent out onto the telephone line.
XFMR is provided to connect the internal 2 to 4 wire converter to the telephone line
transformer. A jumper is required from XFMR to T1 whenever the 2 to 4 wire circuit
T1 is one of two direct connections to the internal telephone line transformer. T1
must be connected to the XE0002D XFMR lead to use the internal 2 to 4 wire
converter. If the 2 to 4 wire converter is not required, Signals for the telephone line
can be passed across T1 and T2.
Hookswitch relay control. A high on OH closes the internal relay and connects the
equipment to the telephone line.
Gnd provides the ground reference connection to the XE0002D.
T2 is one of two direct connections to the internal telephone line transformer. T2
must be connected to Ground to use the internal 2 to 4 wire converter. If the 2 to 4
wire converter is not required, Signals for the telephone line can be passed across T1
Ring is one wire of the two-wire telephone line connection (RJ11 Pin 4). FCC Part
68 Rules require a 1500 volt isolation barrier between the telephone line and all other
circuits. This isolation must be preserved throughout the system. Xecom
recommends 0.100 inch spacing between traces connected to Ring and all other
conductors to preserve this isolation
Tip is one wire of the two-wire telephone line connection (RJ11 Pin 3). The
telephone company places a DC "Battery" voltage across Tip and Ring on all public
switched telephone lines. The XE0002D accept this line battery voltage without
regard to its polarity.
XE0002D Electrical Specifications (VCC = 5V + 10%, Ta = 0 to 70C)
Power Supply Current
Transmit Insertion loss
600 Ohm Impedance, 1000 Hz
Receive Insertion loss
600 Ohm Impedance, 1000 Hz
Line Matching Resistor (Rm)
for 600 ohm telephone line
At 1000 Hz, Rm equal to 340 ohms
without internal 2/4 wire convertor
Attenuation between transmitter input and
receiver output at 1KHz with 600 ohm
Transmit Input Impedance
At XMIT, 1800 Hz
Receive Output Impedance
At RCVR, 1800 Hz
Ring Detect Sensitivity
Min. AC voltage between Tip & Ring
Type B ringer
Ring Indicate Output
Ring Voltage present on Tip and Ring
Hook Switch Control Voltage
Hook Switch Control Current
Telephone Line Loop Current
XE0002D Absolute Maximum Ratings
Operating Temperature Range
0C to +70C
Maximum Lead Temperature
(soldering 2 seconds per wave)
XE0002D Typical Connection Diagram with Internal 2/4 Wire Converter
10 ohms, 1/2 W
10 ohms, 1/2 W
XE0002D Typical Connection Diagram without Internal 2/4 Wire Converter
10 ohms, 1/2 W
10 ohms, 1/2 W
R1 and R2 each equal one half of the ideal line matching impedance, 170 ohms.
XE0002D FCC Instructions
When developing a product to be connected to the telephone line, it is necessary to use a circuit described as
a Data Access Arrangement (DAA) which is approved by the appropriate governmental agency. In the US,
for example, this agency is the Federal Communications Commission (FCC), while in Canada it is the
Department of Communications (DOC). These agencies test and approve the product to ensure that it
meets their specifications, thereby protecting the telephone system from damage and protecting the user
from high voltage transients (such as lightning strikes) which may come down the telephone line.
The XE0002D has been designed to meet all FCC Part 68 requirements for hazardous voltage, surge
protection and leakage current. If the system developed transmits data, or DTMF tones on the telephone
line, the user must certify that the signals transmitted meet basic FCC requirements for maximum
transmission levels, out of band energy and billing delay. Full details may be obtained from the FCC under
Part 68 of the FCC Rules and Regulations, or in Title 47 of the Code of Federal Regulations, however the
basic requirements are as follows:
1. Maximum Transmit Level
For the normal “permissive” (standard) telephone line, equipment which transmits data (such as a modem)
must not exceed a transmission level of -9 dBm.
2. Out of Band Energy
Data equipment must not transmit “out of band” energy on the telephone line which exceeds the following
3. DTMF Transmission Level
If the system is capable of DTMF dialing, the maximum DTMF transmission level must be less than 0 dBm
averaged over a 3 second interval.
4. Billing Delay
A delay of 2 seconds or greater is required after the time the XE0002D is taken “off hook” and before any
information is transmitted. This is required to ensure that billing information may be exchanged between
telephone company central offices without interference.
The user of the XE0002D must certify to the FCC that the final system meets the requirements of Part 68
which include the criteria above as well as the high voltage protection provided by the XE0002D. This is
generally accomplished through an independent testing lab which tests the System and submits the proper
paperwork to the FCC for approval. Since the XE0002D already complies with FCC Part 68 rules, this is a
relatively simple process.
Terms of Sale
Devices sold by XECOM are covered by the warranty provisions appearing in its Terms of Sale only. XECOM
makes no warranty, express, statutory, implied, or by description regarding the information set forth herein, or
regarding the freedom of the described devices from patent infringement. XECOM makes no warranty of
merchantability or fitness for any purposes. XECOM reserves the right to discontinue production and change
specifications and prices at any time and without notice. This product is intended for use in normal commercial
applications. Applications requiring extended temperature range, unusual environmental requirements, or high
reliability applications, such as military, medical life-support or life-sustaining equipment, are specifically not
recommended without additional processing and authorization by XECOM for such application.
Xecom assumes no responsibility for the use of any circuitry other than circuitry embodied in a Xecom product.
No other circuits, patents, or licenses are implied.
Life Support Policy
Xecom's products are not authorized for use as Critical Components in Life Support Devices or Systems.
Life Support Devices or Systems are devices or systems which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions pro-
vided in the labeling, can be reasonably expected to result in significant injury to the user.
A Critical Component is any component of a life support device or system whose failure to perform can be rea-
sonably expected to cause failure of the life support device or system, or to affect its safety or effectiveness.
Copyright, Xecom © 2005
While Xecom, Inc. has made every effort to ensure that the information presented here is accurate, Xecom will not be
liable for any damages arising from errors or omission of fact. Xecom reserves the right to modify specifications and/
or prices without notice. Product mentioned herein are used for identification purposes only and may be trademarks
and/or registered trademarks of their respective companies.
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