4
DP83223
2.0 Pin Description
DP83223 Pinout Summary
Symbol Pin No
PLCC(PQFP)
Type Description
V
CC
13,26 (10, 25) Supply Vcc: Positive power supply for the ECL compatible circuitry. The
Transceiver operates from a single +5VDC power supply.
GND 14, 22(11 ,20) Supply GND: Return path for the ECL compatible circuitry power supply.
RXVcc 4, 27(26, 31) Supply Receive Vcc: Positive power supply for the small signal receive circuitry.
This power supply is intentionally separated from others to eliminate
receive errors due to coupled supply noise.
RXGND 3, 28(27, 30) Supply Receive GND: Return path for the receive power supply circuitry. This
power supply return is intentionally separated from others to eliminate
receive errors due to coupled supply noise.
TXVcc 5, 11(1, 7) Supply Transmit Vcc: Positive power supply required b y the analog portion of the
transmit circuitry. This power supply is intentionally separated from the
others to prevent supply noise from coupling to the transmit outputs.
TXGND 7, 10(3, 6) Supply Transmit GND: Return path for the analog transmit po wer supply circuitry.
This supply return is intentionally separated from others to prevent supply
noise from being coupled to the transmit outputs.
EXTVcc 23(21) Supply External Vcc: Positive power supply for ECL output circuitry.
RXI+/- 2, 1(29, 28) Differential
Voltage In
Receive Data Inputs: Balanced differential line receiver inputs.
PMID+/- 25, 24(23, 22) ECL Out Physical Media Indicate Data: Differential ECL compatible outputs
source the recovered receive data back to the Physical Layer device or to
a separate clock recovery device.
PMRD+/- 15, 16(12,13) ECL In Physical Media Request Data: Differential ECL compatible inputs which
receive data from Physical Layer Device.
TXO+/- 9, 8(5,4) Differential
Current
Out
Transmit Data Outputs: Differential current driver outputs which drive
MLT-3 encoded data over twisted pair cable. These outputs provide
controlled rise and fall times designed to filter the transmitters output which
helps to reduce associated EMI.
SD+/- 20, 21(18, 19) ECL Out Signal Detect Outputs: Differential ECL compatible Signal Detect outputs
indicating that either a signal with the proper amplitude is present at the
RXI+/- inputs or that Loopback mode has been selected.
TXREF 6(2) Current
Out
Transmit Amplitude Reference: Reference current pin allowing
adjustment of TXO+/- transmit amplitude. By placing a resistor between
this pin and GND, a reference current is setup which results in a given
transmit amplitude for a given application. Refer to Functional Description
in Section 3.1 for reference current equations.
ENCSEL 12(9) CMOS In Encode Select Input: The TTL compatible CMOS Encode Select input
controls the encoded state of the signal at the TXO+/- outputs. A logic low
level at this input causes the TXO outputs to become MLT-3 encoded with
the receiver programmed to accept MLT-3 encoded data. This is the
recommended mode of operation. A logic high level causes the TXO pins
to output standard two-level binary code and the receiver is conditioned to
receive a two-level binary signal. The DP83223V does not guarantee this
mode(binary) of operation.
LBEN 19(17) CMOS In Loopback Enable: TTL compatible CMOS Loopback Enable input pin
selects the internal loopback path which routes the PMRD+/- data to the
PMID+/- differential outputs and forces Signal Detect true. During
loopback, data present at the RXI+/- inputs is ignored. However, binary
data is still transmitted by the TXO+/- outputs (regardless of the state of the
ENCSEL input). Loopback mode is selected when LBEN is forced high.
Normal operation occurs when LBEN is forced low.