XRT73L03 Datasheet, PDF (36/62 Pages) Exar Corporation – 3 CHANNEL E3/DS3/STS-1 LINE INTERFCE UNIT

XRT73L03 3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. P1.0.13
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PRELIMINARY
Transformer Recommendations
PARAMETER
VALUE
Turns Ratio
1:1
Primary Inductance
4µH
Isolation Voltage
1500Vrms
Leakage Inductance
0.06µH
PART #
PE-68629
PE-65966
PE-65967
T3001
INSULATION
3000V
1500V
1500V
1500V
PACKAGE TYPE
Large Thru-Hole
Small Thru-Hole
Small SMT
Small SMT
TRANSFORMER VENDOR INFORMATION
Pulse
Corporate Office
12220 World Trade Drive
San Diego, CA 92128
Tel: [phone]
FAX: [phone]
Europe
1 & 2 Huxley Road
The Surrey Research Park
Guildford, Surrey GU2 5RE
United Kingdom
Tel: [phone]
FAX: [phone]
Asia
150 Kampong Ampat
#07-01/02
KA Centre
Singapore 368324
Tel: [phone]
FAX: [phone]
3.0 THE RECEIVE SECTION
Figure 8 indicates that the Receive Section in the
XRT73L03 consists of the following blocks:
• AGC/Equalizer
• Peak Detector
• Slicer
• Clock Recovery PLL
• Data Recovery
• HDB3/B3ZS Decoder
The purpose of each Receive Section of the
XRT73L03 is to take an incoming attenuated/distort-
ed bipolar signal from the line and encode it back into
the TTL/CMOS format where it can be received and
processed by the Terminal Equipment.
3.1 INTERFACING THE RECEIVE SECTIONS OF THE
XRT73L03 TO THE LINE
The design of the Receive Circuitry in the XRT73L03
allows for transformer-coupling or capacitive-coupling
of the Receive Section to the line. As mentioned ear-
lier, the specification documents for E3, DS3 and
STS-1 all specify 75 Ohm termination loads when
transmitting over coaxial cable. The recommended
method of Transformer-Coupling the Receive Section
of the XRT73L03 to the line is shown in Figure 17 and
the Capacitive-Coupling method is shown in Figure
18.
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