HFBR-1116T Datasheet, PDF (5/11 Pages) Agilent(Hewlett-Packard) – Fiber Optic Transmitter and Receiver Data Links for 155 MBd

Shipping Container
The data link modules are
packaged in a shipping container
designed to protect it from
mechanical and ESD damage
during shipment or storage.
Board Layout–Interface
Circuit and Layout
Guidelines
It is important to take care in the
layout of your circuit board to
achieve optimum performance
from these data link modules.
Figure 7 provides a good example
of a power supply filter circuit that
works well with these parts. Also,
suggested signal terminations for
the Data, Data-bar, Signal Detect
and Signal Detect-bar lines are
shown. Use of a multilayer,
ground-plane printed circuit board
will provide good high-frequency
circuit performance with a low
inductance ground return path. See
additional recommendations noted
in the interface schematic shown in
Figure 7.
+5 Vdc
GND
DATA
DATA
Tx
*
A
L2
1
C2
0.1
R3 R2 R4 R1
82 82 130 130
9 NC
10 GND
11 V_CC
12 V_CC
13 GND
14 D
15 D
16 NC
NC 8
NO
PIN
7
GND 6
GND 5
GND 4
GND 3
V_BB 2
NC 1
C5
0.1
TERMINATE D, D
AT Tx INPUTS
Rx
* _{9 NC}
NC 8
10
NO
PIN
11 GND
GND 7
V_CC 6
12 GND V_CC 5
13 GND V_CC 4
14 SD
D3
15 SD
16
NO
PIN
D2
NC 1
TOP VIEWS
L1
1
C1
C7
C3
C4
0.1
10
0.1
10
(OPTIONAL)
R7 R5 R8 R6
82 82 130 130
C6
0.1
R9
82
R11
82
SD
R10 R12
130 130
A
DATA
DATA
SD
TERMINATE D, D, SD, SD AT
INPUTS OF FOLLOW-ON DEVICES
NOTES:
1. RESISTANCE IS IN OHMS. CAPACITANCE IS IN MICROFARADS. INDUCTANCE IS IN MICROHENRIES.
2. TERMINATE TRANSMITTER INPUT DATA AND DATA-BAR AT THE TRANSMITTER INPUT PINS. TERMINATE THE RECEIVER OUTPUT DATA, DATA-BAR, AND SIGNAL DETECT-
BAR AT THE FOLLOW-ON DEVICE INPUT PINS. FOR LOWER POWER DISSIPATION IN THE SIGNAL DETECT TERMINATION CIRCUITRY WITH SMALL COMPROMISE TO THE
SIGNAL QUALITY, EACH SIGNAL DETECT OUTPUT CAN BE LOADED WITH 510 OHMS TO GROUND INSTEAD OF THE TWO RESISTOR, SPLIT-LOAD PECL TERMINATION
SHOWN IN THIS SCHEMATIC.
3. MAKE DIFFERENTIAL SIGNAL PATHS SHORT AND OF SAME LENGTH WITH EQUAL TERMINATION IMPEDANCE.
4. SIGNAL TRACES SHOULD BE 50 OHMS MICROSTRIP OR STRIPLINE TRANSMISSION LINES. USE MULTILAYER, GROUND-PLANE PRINTED CIRCUIT BOARD FOR BEST HIGH-
FREQUENCY PERFORMANCE.
5. USE HIGH-FREQUENCY, MONOLITHIC CERAMIC BYPASS CAPACITORS AND LOW SERIES DC RESISTANCE INDUCTORS. RECOMMEND USE OF SURFACE-MOUNT COIL
INDUCTORS AND CAPACITORS. IN LOW NOISE POWER SUPPLY SYSTEMS, FERRITE BEAD INDUCTORS CAN BE SUBSTITUTED FOR COIL INDUCTORS. LOCATE POWER
SUPPLY FILTER COMPONENTS CLOSE TO THEIR RESPECTIVE POWER SUPPLY PINS. C7 IS AN OPTIONAL BYPASS CAPACITOR FOR IMPROVED, LOW-FREQUENCY NOISE
POWER SUPPLY FILTER PERFORMANCE.
6. DEVICE GROUND PINS SHOULD BE DIRECTLY AND INDIVIDUALLY CONNECTED TO GROUND.
7. CAUTION: DO NOT DIRECTLY CONNECT THE FIBER-OPTIC MODULE PECL OUTPUTS (DATA, DATA-BAR, SIGNAL DETECT, SIGNAL DETECT-BAR, VBB) TO GROUND WITHOUT
PROPER CURRENT LIMITING IMPEDANCE.
8. (*) OPTIONAL METAL ST OPTICAL PORT TRANSMITTER AND RECEIVER MODULES WILL HAVE PINS 8 AND 9 ELECTRICALLY CONNECTED TO THE METAL PORT ONLY AND
NOT CONNECTED TO THE INTERNAL SIGNAL GROUND.
Figure 7. Recommended Interface Circuitry and Power Supply Filter Circuits.
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