ETC XE0020C

XE0020 and XE0020C
8/97
Telephone Line Interface with Active Line Monitoring
Description
The XE0020 and XE0020C are complete compact
telephone interface modules. As with all Xecom
DAAs the XE0020 and XE0020C include Ring
Detection, Switch-Hook, and Loop Current
Holding Circuits. In addition both the XE0020 and
XE0020C include two line monitors to insure
unobtrusive customer premises operation. The
XE0020C also passes the Caller ID signal through
to the system host.
Features
* Small Size: 2.0" by 0.5" by 0.4" thick;
* Supports data transfer at 33,600 bps;
* FCC Part 68 Compliant;
* Ring Detection;
* Continuous Connect Detect Monitor;
* Handset Interrupt Monitor
* Single +5 Volt Power Supply;
* Hookswitch Control
Xecom designed the XE0020 and XE0020C for
unobtrusive operation in residential applications.
Two integral line monitors prevent interference
with the residents calls.
Connect Detect verifies line availability before the
equipment seizes the line. This will prevent the
equipment from interrupting a residents call.
* Caller ID Signal Path (XE0020C)
Models
XE0020: includes ring detect , hookswitch,
Handset Interrupt, Connect Detect, telephone
line transformer, loop current holding circuit;
XE0020C: XE0020 features plus Caller ID signal
pass through;
Handset Interrupt signals the system host to
drop the call in progress when the resident picksup an extension phone. This feature permits the
resident to interrupt the call in case of emergency.
Block Diagram
Caller ID permits the host to
identify incoming calls and
answer only those from
designated call centers.
Caller ID
(optional)
TIP
T1
Together these features give
residents priority use of the
telephone line without shutting
out the equipment.
T2
OH
RI
Line
Transformer
Loop
Current
Holding
Circuit
RING
HookSwitch
Ring
Detect
HInt
CD
XECOM
Line
Voltage
Monitor
XE0020
Mechanical Specifications
Inches
Dim Min
Max
Millimeters
Min
Max
A
B
C
-
0.400
0.520
2.020
-
10.16
13.21
51.05
D
E
F
G
H
0.040
0.090
0.790
0.490
0.390
0.060
0.110
0.810
0.510
0.410
1.02
2.29
20.07
12.45
9.91
1.52
2.79
20.57
12.95
10.41
I
J
0.040
0.125
0.060
0.200
1.02
3.18
1.52
5.08
B
C
A
J
E
E
F
G
I
H
D
D
E
Pin Size: 0.025" by 0.025"
Recommended hole size: 0.056"
All pins tin-plated.
XE0020/XE0020C Pin Configuration & Descriptions
bottom view
1 2
3 4 5 6 7 8
o
o
o
Ring Tip
Pin
1
Name
o
o
o
o
o
OH T1 Gnd Vcc T2 /RI
9 10
o
o
HInt /CD
Description
Ring
Ring is one of two signals which form the telephone network connection (RJ11 Pin 4). The
XE0020 is not sensitive to the polarity of the battery voltage on the telephone line. Ring has
1500 volts isolation from the rest of the circuitry which must be preserved throughout the
system.
2
Tip
Tip provides the second connection to the telephone network (RJ11 Pin 3). Tip has 1500
volts isolation from the rest of the circuitry. This isolation must be preserved throughout the
system.
3
OH
Hook-switch relay control an active high input. A high on OH closes the internal relay and
connects the equipment to the telephone line.
4
T1
T1 connects directly to the secondary side of the XE0020's internal telephone line
transformer.
5
GND
This signal is used as common reference for all of the control signals in the XE0020. Signals
on T1 and T2 are not referenced to ground.
XECOM
(2)
XE0020
Pin Descriptions continued
Pin
Name
Description
6
VCC
7
T2
T2 connects directly to the secondary side of the XE0020"s internal telephone line
transformer.
8
/RI
Ring Indicate, output, active low, TTL, RI provides a ring frequency pulse train representation.
An external 56K pull-up resistor is required to correctly bias the ring indicate output.
9
HInt
Handset Interrupt is an active high output from the modem. HInt goes high for one second if
an extension telephone is picked-up while the DAA has control of the line. When the host
sees HInt go high, it should immediately lower OH to disconnect the XE0020 or XE0020C
from the telephone line.
10
/CD
Connect Detect, output, active low, TTL. /CD indicates that the XE0020 is connected to the
telephone line and the telephone line is not in use.
VCC provides the + 5 volt power source for the XE0020.
XE0020/XE0020C Typical Connection Diagram
+5 Volts
RJ11
Modem
Data Pump
VCC
15 Ohms 1/2 W
FB2
4
C2
56K
MOV1
Tip
3
/RI
Ring
RXA
Ring
15 Ohms 1/2 W
C3
T1
340 ohms
Z1
Z2
TXA1
FB1
TXA2
C1
T2
OH
Off Hook
Controller
HInt
/CD
Gnd
Recommended Parts
Designation
C1
Description
.01 Microfarad
C2,C3
47 pico farad, 3000 volts
Z1, Z2
Zener Diode, 4.3 volts
FB1, FB2
MOV1
XECOM
Ferrite Beads (TDK Part Number CCB30-453215B)
Minimum Breakover 220 volts (Teccor Electronics Part Number P2600BA70)
(3)
XE0020
Electrical Specification (Vcc=+3v ±10%, Ta=0 to 70 deg C)
Parameter
Conditions
Min
Typ
Max
Units
10
15
mA
Power Supply Current
Off Hook, 5.0 Volts
Transmit Insertion loss
600 Ohm Impedance, 1000 Hz
1.7
2.7
3.7
dB
Receive Insertion loss
600 Ohm Impedance, 1000 Hz
1.7
2.7
3.7
dB
Line Impedance
At 1000 Hz, Rm 340 ohms
540
600
660
Ohms
Coupler Match
input impedance
Input impedance to T1 & T2
330
340
350
Ohms
Ring Detect
Sensitivity (on-hook)
Min. AC voltage between Tip &
Ring Type B ringer
38
150
Vrms
Ring Detect
Peak Current
Ringing voltage of 40 Vrms
applied between Tip & Ring
100
Ring Detect
Idle Current
No Ringing Voltage present
Ring Indicate Output
Voltage
Ring Voltage present on Tip
& Ring
Loop Current Switch
Control Voltage
ON: (off-hook)
OFF: (on-hook)
2.0
Loop Current Switch
Control Current
Loop Current
Off-Hook current draw from
Telephone Line
20
Total Harmonic
Distortion
At 1800 Hz, -9 dBm signal level
-72
Connect Detect
Threshold
Handset Interrupt
Battery Voltage Change
At Tip and Ring
40 milliamps loop current
0.5
uA
10
uA
0.2
0.5
Volts
3.0
0.2
0.5
Volts
Volts
15
25
mA
100
mA
-76
dBm
15
Volts
1.0
1.5
Volts
ABSOLUTE MAXIMUM RATINGS
Storage Temperature
Operating Temperature Range
Maximum Lead Temperature (soldering 2 seconds per wave)
XECOM
(4)
-25OC to +85OC
0OC to +70OC
260OC
XE0020
Telephone Line Connection Information
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 Industry Canada.
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 XE0020 has been designed to meet FCC Part 68 requirements for hazardous voltage, surge protection and
leakage current. If the system transmits data, or DTMF tones on the telephone line, the user must certify that these
transmitted signals meet FCC requirements for maximum transmission levels of 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 limits:
Frequency
Range
Max. Power
200Hz
to
3990Hz
-9 dBm
3990Hz
to
4005Hz
-27 dBm
4005Hz
to
16kHz
-16 dBm
8kHz
to
94kHz
-47 dBm
86kHz
to
270kHz
-46 dBm
270kHz
to
6MHz
-6 dBm
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 XE0020 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 XE0020 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 isolation provided by the XE0020. This is generally
accomplished through an independent testing lab which test the System and submits the proper paperwork to the
FCC for approval. Since the XE0020 already complies with FCC Part 68 rules, this is a relatively simple process.
XECOM
(5)
XE0020
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
provided 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
reasonably expected to cause failure of the life support device or system, or to affect its safety or effectiveness.
Copyright, Xecom © 1997
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.
Xecom Incorporated
374 Turquoise Street, Milpitas, CA 95035
Web Site www.xecom.com
Ph:408 -945 -66 40 Fax: 408 - 942-1346 E-Mail [email protected]
XECOM
(6)
XE0020