
10
Table 1. Pinout Table
Pin
Symbol
Mounting Pins The mounting pins are provided for transceiver mechanical attachment to the circuit board.
They are embedded in the nonconductive plastic housing and are not connected to the
transceiver internal circuit, nor is there a guaranteed connection to the metallized housing
in the EM and FM versions. They should be soldered into plated-through hole on the
printed circuit board.
1
V
EER
Receiver Signal Ground
Directly connect this pin to receiver signal ground plane. (For HFBR-53D3, V
EER
= V
EET
)
2
RD+
Receiver Data Out
RD+ is an open-emitter output circuit. Terminate this high-speed differential PECL output
with standard PECL techniques at the follow-on device input pin.
3
RD–
Receiver Data Out Bar
RD– is an open-emitter output circuit. Terminate this high-speed differential PECL output
with standard PECL techniques at the follow-on device input pin.
4
SD
Signal Detect
Normal optical input levels to the receiver result in a logic “1” output, V
OH
, asserted.
Low input optical levels to the receiver result in a fault condition indicated by a logic “0”
output V
OL
, deasserted.
Signal Detect is a single-ended PECL output. SD can be terminated with standard PECL
techniques via 50
to V
CCR
- 2 V. Alternatively, SD can be loaded with a 270
resistor to
V
EER
to conserve electrical power with small compromise to signal quality. If Signal Detect
output is not used, leave it open-circuited.
This Signal Detect output can be used to drive a PECL input on an upstream circuit, such
as, Signal Detect input or Loss of Signal-bar.
5
V
CCR
Receiver Power Supply
Provide +5 V dc via the recommended receiver power supply filter circuit.
Locate the power supply filter circuit as close as possible to the V
CCR
pin.
6
V
CCT
Transmitter Power Supply
Provide +5 Vdc via the recommended transmitter power supply filter circuit.
Locate the power supply filter circuit as close as possible to the V
CCT
pin.
7
TD–
Transmitter Data In-Bar
Terminate this high-speed differential PECL input with standard PECL techniques at the
transmitter input pin.
8
TD+
Transmitter Data In
Terminate this high-speed differential PECL input with standard PECL techniques at the
transmitter input pin.
9
V
EET
Transmitter Signal Ground
Directly connect this pin to the transmitter signal ground plane.
Functional Description
Figure 2. Pin-Out
1 = V
EER
2 = RD+
3 = RD–
4 = SD
5 = V
CCR
6 = V
CCT
7 = TD–
8 = TD+
9 = V
EET
TOP VIEW
NIC
NIC
RX
TX
NIC = NO INTERNAL CONNECTION (MOUNTING PINS)