XRT82D20IW Exar Corporation, XRT82D20IW Datasheet - Page 20

• Manufacturer Part Number: XRT82D20IW
• Description: IC LIU EI SGL 28SOJ
• Manufacturer: Exar Corporation

Specifications of XRT82D20IW

• Product: Framer
• Lead Free Status / RoHS Status: Contains lead / RoHS Compliant

XRT82D20
SINGLE CHANNEL E1 LINE INTERFACE UNIT
Capacitive coupling provides a lower cost interface to the line. It must be noted that the line isolation is limited
to the breakdown voltage of the capactior versus the typical transformer isolation of 1,500 to 3,000 volts. With
a capacitor there is also no DC isolation to ground as there is with with a transformer.
Applications that are not sensitive to these issues can benefit from the lower cost approach of using capacitor
coupling on the receive input.
See
coupling the receiver to the line.
N
F
1.6
OTE
IGURE
R Load
: Resistive divider attenuates the input signal by one-half for both 75
Figure
75 Ω
Source
Signal
75 Ω
14. C
Capacitively-coupling the Receive Section(s) of the XRT82D20 to the line
14,
APACITIVELY
75 Ω Coax
Figure
75 Ω Coax
15,
-
COUPLING THE
Figure 16
37.4 Ω
2:1
and
R
ECEIVE
Figure 17
37.4 Ω
S
9.1 Ω
9.1 Ω
ECTION FOR
0.1 µF
0.1 µF
19
for
the recommended schematics for capacitively
RRING
TRING
Rx Input
Tx Output
RTIP
TTIP
75 O
Ω
HM
and 120
A
PPLICATION AND
Ω
RPOS/RData
TNEG/CODE
TPOS/TData
applications.
RNEG/LCV
TxLEV
AGND
AVDD
TGND
TVDD
RClk
TClk
3.3V
10µF
SUPPLY
REV. 1.0.8
+3.3 V
0.1µF