XRT82D20_06 Datasheet, PDF (21/27 Pages) Exar Corporation – SINGLE CHANNEL E1 LINE INTERFACE UNIT

REV. 1.0.8
XRT82D20
SINGLE CHANNEL E1 LINE INTERFACE UNIT
FIGURE 15. CAPACITIVELY-COUPLING THE RECEIVE SECTION FOR 120 OHM APPLICATION AND 3.3V SUPPLY
120 Ω Twisted Pair
120 Ω
Signal
Source
30.1 Ω
30.1 Ω
120 Ω Twisted Pair
2:1
R Load
120 Ω
0.1 µF
60.4 Ω
RTIP
Rx Input
0.1 µF
RRING
9.1 Ω
9.1 Ω
TTIP
Tx Output
TRING
RPOS/RData
RNEG/LCV
RClk
TVDD
AVDD
10 µF
TxLEV
TGND
AGND
+3.3 V
0.1µF
TNEG/CODE
TPOS/TData
TClk
NOTE: Resistive divider attenuates the input signal by one-half for both 75 Ω and 120 Ω applications.
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