afbr-820bz Avago Technologies, afbr-820bz Datasheet - Page 5

• Manufacturer Part Number: afbr-820bz
• Description: Twelve-channel Transmitter And Receiver Pluggable, Parallel-fiber-optic Modules
• Manufacturer: Avago Technologies

Data
Receiver Output Amplitude and De-emphasis
Receiver outputs can be programmed to provide several
levels of amplitude and de-emphasis. See Figure 5 for
de-emphasis definition. The user can program for peak-
to-peak amplitude and then a de-emphasis level. If zero
de-emphasis is selected, then the signal steady state equals
the peak-to-peak level. For other levels of de-emphasis the
selected de-emphasis reduces the steady-state from the
peak-to-peak level. The change from peak-to-peak level to
steady-state occurs within a bit time. See Rx Memory Map
01h Upper Page section addresses 228 - 233 for amplitude
programming details and addresses 234 – 239 for
de-emphasis programming details. For optimal performance at
10 Gb/s, changing the default De-emphasis settings is NOT recommended.
Figure 5. Definition of De-emphasis and Steady State
Control Signal Interface
The control interface includes dedicated signals for
address inputs, interrupt output and reset input and bidi-
rectional clock and data lines for a two-wire serial access
(TWS interface) to control and status and information
registers. The TWS interface is compatible with industry
standard two-wire serial protocol scaled for 3.3 volt LVTTL.
It is implemented as a slave device. Signal and timing
characteristics are further defined in the Control Charac-
teristics and Control Interface & Memory Map sections.
The registers of the serial interface memory are defined in
the Control Interface & Memory Map section.
Regulatory & Compliance Issues
Various standard and regulations apply to the modules.
These include eye-safety, EMC, ESD and RoHS. See the Reg-
ulatory Section for details regarding these and component
recognition. Please note the transmitter module is a Class
1M laser product – DO NOT VIEW RADIATION DIRECTLY
WITH OPTICAL INSTRUMENTS. See Regulatory Compliance
Table for details. When released, the AFBR- will support
this table.
5
Voltage
Output
0
1
0
0
0
1
0
1 bit
1
De-Emphasis % = (DE/SS)(100%)
1
1
Steady-State (SS)
De-Emphasis (DE)
Package Outline
The module is designed to meet the package outline
defined in the PPOD MSA. This MSA follows the outline
of the SNAP12 MSA except for the position of the MEG-
Array£ connector and pin assignments. See the package
outline and host board footprint figures (Figures 23 -26)
for details.
Handling and Cleaning
The transmitter and receiver modules can be damaged
by exposure to current surges and over voltage events.
Care should be taken to restrict exposure to the condi-
tions defined in the Absolute Maximum Ratings. Wave
soldering, reflow soldering and/or aqueous wash process
with the modules on board are not recommended. Normal
handling precautions for electrostatic discharge sensitive
devices should be observed.
Each module is supplied with an inserted port plug for
protection of the optical ports. This plug should always be
in place whenever a fiber cable is not inserted.
The optical connector includes recessed elements that
are exposed whenever a cable or port plug is not inserted.
Prior to insertion of a fiber optic cable, it is recommended
that the cable end be cleaned to avoid contamination
from the cable plug. The port plug ensures the Optic
remain clean and no addition cleaning should be needed.
In the event of contamination, dry nitrogen or clean dry
air at less than 20 psi can be used to dislodge the contami-
nation. The optical port features (e.g. guide pins) preclude
use of a solid instrument. Liquids are also not advised.