Specifications

Reference Design HFRD-25.2 (Rev.8; 01/09) Maxim Integrated Products
Page 36 of 42
12 Evaluation Quick Start
12.1 Evaluation Notice
The HFRD-25.2 reference design has DC-coupled
I/O (see Sections
13 and 15) and a large optical
output signal (approximately -1.0dBm to
+1.0dBm). When evaluating the HFRD-25.2
reference design, ensure that proper connections
are made to the test equipment. Also check that all
signal levels are within the proper range
(common-mode, differential swing, optical
input/output power, etc.) to avoid damage to the
test equipment or reference design.
Precautions must also be taken to ensure safe
operation when using a device with a laser diode.
Laser light emissions can be harmful and may
cause eye damage. Maxim assumes no
responsibility for harm, injury, or test equipment
damage as a result of the use of this reference
design.
12.2 Evaluation Setup
Carefully make the following connections to the
HFRD-25.2 board:
1.
Clean and inspect the fiber pigtail
connector and then recap the fiber
connector. In all of the following steps,
handle the fiber with care, assuming that
laser light could be emitted from the laser
diode and to avoid eye or equipment
damage.
2.
Connect the fiber pigtail to an optical
attenuator and/or optical to electrical
converter. Note that the output of the laser
pigtail can be in excess of 2dBm. Use safe
handling procedures and use an optical
attenuator, if needed, to ensure that the
power level is within the safe operating
limits of the test equipment.
3.
Connect the HFRD-25.2 into the HFRD-
26.0 SFF Host Board. Follow the
instructions in the HFRD-26.0 document
(http://www.maxim-
ic.com/products/fiber/reference_designs.c
fm) for installing the software and setting
up the HFRD-26.0 board connections.
4.
To complete the setup, review the
schematic carefully, noting the DC-
coupled connections of TD. Make the
appropriate optical and electrical
connections using the Recommended
Operating Conditions (Page 5) and SFF
Module Pin Description (Page 38)
sections as a reference. If assistance is
required, please email questions to:
https://support.maxim-
ic.com/tech_support/submit_question.mv
p?pl_id=5.
5.
The modules operation and status can be
controlled through the software provided
with the HFRD-26.0 Host Board (
Figure
10
). A jumper is also provided for ISP
programming of the μC. The software
provides the user with the following
features to aide in the evaluation and
further development of the reference
design:
a.
Ability to read all memory
locations and registers.
b.
Supply current and voltage
monitors for RX and TX sections.
c.
Adjustable supply voltage.
d.
Access to μC reset.
e.
Auto-updating of monitor values.
f.
Mode configuration menu.
g.
Simplified LUT reading/writing
instant-on bias current values.
h.
Read and write access to all
available EEPROM and SRAM
memory locations.
Additional details of the use and setup of
the GUI software and host board (HFRD-
26.0) are provided in the HFRD-26.0
document
(http://www.maxim-ic.com/products/fiber/
reference_designs.cfm
).