L80223 LSI, L80223 Datasheet - Page 34

• Manufacturer Part Number: L80223
• Manufacturer: LSI

Specifications of L80223

• Lead Free Status / RoHS Status: Not Compliant

2.3.7.2 10 Mbits/s TP Transmitter
2-16
The line driver converts the shaped and smoothed waveform to a current
output that can drive greater than 100 meters of category 5 unshielded
twisted-pair cable or 150-ohm shielded twisted-pair cable.
Even though the 10 Mbits/s transmitter operation is much different than
that of 100 Mbits/s, it also consists of a waveform generator and line
driver (see
The waveform generator, which consists of a ROM, DAC, clock
generator, and filter, shapes the output transmit pulse. The DAC
generates a stair-stepped representation of the desired output waveform.
The stair-stepped DAC output then is passed through a low-pass filter to
“smooth” the DAC output and remove any high-frequency components.
The DAC values are determined from the data at the ROM addresses.
The data is chosen to shape the pulse to the desired template. The clock
generator clocks the data into the DAC at high speed. In this way, the
waveform generator preshapes the output waveform to be transmitted
onto the twisted-pair cable to meet the pulse template requirements
outlined in IEEE 802.3 Clause 14 and shown in
waveshaper replaces and eliminates external filters on the TP transmit
output.
The line driver converts the shaped and smoothed waveform to a current
output that can drive greater than 100 meters of category 3/4/5 100-ohm
unshielded twisted-pair cable or 150-ohm shielded twisted-pair cable
without any external filters.
During the idle period, no output signals are transmitted on the TP
outputs except for link pulses.
Functional Description
Figure
Copyright © 2000, 2001, 2002 by LSI Logic Corporation. All rights reserved.
2.1).
Figure
2.4. The