XRT82D20ES Exar, XRT82D20ES Datasheet - Page 14

• Manufacturer Part Number: XRT82D20ES
• Description: Peripheral Drivers & Components - PCIs 1 CH E1 LIU
• Manufacturer: Exar

Specifications of XRT82D20ES

• Product Category: Peripheral Drivers & Components - PCIs
• Rohs: yes

XRT82D20
SINGLE CHANNEL E1 LINE INTERFACE UNIT
In general, if the XRT82D20 samples a “1” on the TPOS input pin, then the Transmit Section will ultimately
generate a positive polarity pulse via the TTIP and TRing output pins (across a 1:2 transformer). Conversely, if
the XRT82D20 samples a “1” on the TNEG input pin, then the Transmit Section of the device will ultimately
generate a negative polarity pulse via the TTIP and TRing output pins (across a 1:2 transformer).
The purpose of the Transmit Pulse Shaping circuit is to generate Transmit Output pulses that comply with the
ITU-T G.703 Pulse Template Requirements for E1 Applications.
An illustration of the ITU-T G.703 Pulse Template Requirements is presented below in
With input signal as described above, the XRT82D20 will take each mark (which is provided to it via the
Transmit Input Interface block, and will generate a pulse that complies with the pulse template, presented in
Figure 9
F
1.3
IGURE
8. I
The Pulse Shaping Circuit
(when measured on the secondary side of the Transmit Output Transformer).
LLUSTRATION ON HOW THE
TPOS
TNEG
TClk
tSU
XRT82D20 S
tHO
AMPLES THE DATA ON THE
13
TPOS
AND
Figure
TNEG
9.
INPUT PINS
REV. 1.0.8