1.8 10 Mb/s and 100 Mb/s PMD Interface
Signal Name
TD-, TD+
Type
Pin #
Description
I/O
16, 17
Differential common driver transmit output (PMD Output Pair).
These differential outputs are automatically configured to either
10BASE-T or 100BASE-TX signaling.
In Auto-MDIX mode of operation, this pair can be used as the Re-
ceive Input pair.
These pins require 3.3V bias for operation.
RD-, RD+
I/O
13, 14
Differential receive input (PMD Input Pair). These differential in-
puts are automatically configured to accept either 100BASE-TX
or 10BASE-T signaling.
In Auto-MDIX mode of operation, this pair can be used as the
Transmit Output pair.
These pins require 3.3V bias for operation.
1.9 Special Connections
Signal Name
Type
Pin #
Description
RBIAS
I
24
Bias Resistor Connection. A 4.87 kΩ 1% resistor should be con-
nected from RBIAS to GND.
PFBOUT
O
I
23
Power Feedback Output. Parallel caps, 10µ F (Tantalum pre-
ferred) and 0.1µF, should be placed close to the PFBOUT. Con-
nect this pin to PFBIN1 (pin 18) and PFBIN2 (pin 37). See
Section 5.4 for proper placement pin.
PFBIN1
PFBIN2
18
37
Power Feedback Input. These pins are fed with power from
PFBOUT pin. A small capacitor of 0.1µF should be connected
close to each pin.
Note: Do not supply power to these pins other than from
PFBOUT.
RESERVED
I/O
20, 21
RESERVED: These pins must be pulled-up through 2.2 kΩ resis-
tors to AVDD33 supply.
1.10 Power Supply Pins
Signal Name
IOVDD33
IOGND
Pin #
Description
I/O 3.3V Supply
32, 48
35, 47
36
I/O Ground
DGND
Digital Ground
AVDD33
22
Analog 3.3V Supply
Analog Ground
AGND
15, 19
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