LAN8710A-EZK-TR SMSC, LAN8710A-EZK-TR Datasheet - Page 22

• Manufacturer Part Number: LAN8710A-EZK-TR
• Description: Ethernet ICs 10/100 Ethernet XCVR w/HPAutoMDIX FlexPwr
• Manufacturer: SMSC
• Type: Single Chipr

Specifications of LAN8710A-EZK-TR

• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Product: Ethernet Transceivers
• Number Of Transceivers: 1
• Standard Supported: IEEE 802.3 or IEEE 802.3u
• Data Rate: 125 Mbps
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 1.6 V or 3 V
• Maximum Operating Temperature: + 85 C
• Package / Case: QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Revision 1.2 (11-10-10)
3.1.2
3.1.2.1
3.1.2.2
MAC
Converter
Converter
NRZI
100BASE-TX Receive
The 100BASE-TX receive data path is shown in
following subsections.
100M Receive Input
The MLT-3 from the cable is fed into the transceiver (on inputs RXP and RXN) via a 1:1 ratio
transformer. The ADC samples the incoming differential signal at a rate of 125M samples per second.
Using a 64-level quanitizer, it generates 6 digital bits to represent each sample. The DSP adjusts the
gain of the ADC according to the observed signal levels such that the full dynamic range of the ADC
can be used.
Equalizer, Baseline Wander Correction and Clock and Data Recovery
The 6 bits from the ADC are fed into the DSP block. The equalizer in the DSP section compensates
for phase and amplitude distortion caused by the physical channel consisting of magnetics, connectors,
and CAT- 5 cable. The equalizer can restore the signal for any good-quality CAT-5 cable between 1m
and 150m.
If the DC content of the signal is such that the low-frequency components fall below the low frequency
pole of the isolation transformer, then the droop characteristics of the transformer will become
significant and Baseline Wander (BLW) on the received signal will result. To prevent corruption of the
received data, the transceiver corrects for BLW and can receive the ANSI X3.263-1995 FDDI TP-PMD
defined “killer packet” with no bit errors.
The 100M PLL generates multiple phases of the 125MHz clock. A multiplexer, controlled by the timing
unit of the DSP, selects the optimum phase for sampling the data. This is used as the received
recovered clock. This clock is used to extract the serial data from the received signal.
A/D
Ext Ref_CLK (for RMII only)
RMII 50Mhz by 2 bits
MII 25Mhz by 4 bits
(for MII only)
RX_CLK
NRZI
or
MLT-3
Converter
MLT-3
Magnetics
Figure 3.2 100BASE-TX Receive Data Path
MII/RMII
PLL
MLT-3
DATASHEET
Small Footprint MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR
125 Mbps Serial
by 4 bits
25MHz
MLT-3
6 bit Data
22
RJ45
Figure
Decoder
4B/5B
and BLW Correction
recovery, Equalizer
MLT-3
3.2. Each major block is explained in the
DSP: Timing
CAT-5
25MHz by
5 bits
SMSC LAN8710A/LAN8710Ai
Descrambler
and SIPO
Datasheet
®
Technology