dp83223 National Semiconductor Corporation, dp83223 Datasheet - Page 11

• Manufacturer Part Number: dp83223
• Description: Dp83223 Twister High Speed Networking Transceiver Device
• Manufacturer: National Semiconductor Corporation

The PMRD, SD and PMID 100K ECL differential signal must be
terminated into a standard ECL load of 50 to VCC-2.0V or equivalent:
i.e. Thevenin of 130 to GND accompanied by 82 to VCC
Clock Recovery
Data to PHY or
4.0 DC and AC Specifications
SD To PHY
Device
Data from
Device
Device
Inactive PMID
PHY
Active PMID
0.01uF
Figure 4-3.
GND
V
CC
float
T
ENCSEL
PMRD+
LBEN
VCC
PMRD-
SD+
SD-
PMID+
PMID-
EQSEL
CDET
GND
ypical Schematic for 100BASE-TX signalling over Cat-5 UTP 100 cable
DP83223
Figure 4-2. Post Equalized Signal Detect Voltage
(Continued)
EXTVCC
*The Rref resistor value may need to be adjusted
to compensate for transmit magnetics insertion
loss in order to achieve the standard specific
2.0V pk-pk differential TXO+/- output amplitude
as measured across the RJ45 transmit pins.
RXGND
TXVCC
RXVCC
TXGND
TXREF
Post Equalized Signal Detect Voltage
TXO+
TXO-
VCC
SD
RXI+
RXI-
R
*510
THoff
REF
11
FB
0.01uF
50
12.1
50
37.9
SD
THon
12.1
37.9
FB
Contact National Semiconductor
for further information relating to
available magnetics modules
0.01uF
Please refer to the National Semiconductor Application Note
entitled “DP83223 Adaptive Equalization Considerations”
for further detail. The values provided in this example
are targeted to match an insertion loss of approximately
0.4dB (approximately 90mV pk-pk differential of loss for
a typical scrambled IDLE line state) which will result in
a final amplitude of approximately 1.45V pk-pk differential
as seen across the RXI+/- inputs for zero Meters of cable.
Common Mode Noise Filter
The Receive Attenuation / Termination network
must be optimized to compensate for the insertion
loss of the receive magnetics.
All resistors are 1/10th Wt, 1% tolerance
All capacitors are 16V ceramic
= Murata # BLM31A02PT (1206 package)
Magnetics
Magnetics
Transmit
Receive
1
2
3
4
5
6
7
8
RJ-45