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Avago Technologies Confidential
Receiver
The optical receiver incorporates a 12-channel PIN photo-
diode array, a 12-channel pre-amplifier and output buffer,
diagnostic monitors, and control and bias blocks. The Rx
Output Buffer provides differential outputs for the high
speed electrical interface presenting nominal single-end-
ed output impedances of 50
W
to AC ground and 100
W
differentially that should be differentially terminated with
100
W
. AC coupling capacitors are located inside the CXP
module and are not required on the host board.
Modules have a monitor for optical input power; results
are available through the TWS interface. Alarm thresholds
are established for the monitored attributes. Flags are set
and interrupts generated when the attributes are outside
the thresholds.
Over the TWS interface, the user can, for individual
channels, control (flip) polarity of the differential outputs,
de-activate channels, disable the squelch function,
program output signal amplitude and deemphasis.
Flags are also set and interrupts generated for loss of
optical input signal (LOS). All flags are latched and will
remain set even if the condition initiating the latch clears
and operation resumes. All interrupts can be masked and
flags are reset upon reading the appropriate flag register.
The electrical output will squelch for loss of input signal
(unless squelch is disabled) and channel de-activation
through TWS interface. Status and alarm information are
available via the TWS interface. To reduce the need for
polling, the hardware interrupt signal is provided to inform
hosts of an assertion of an alarm and/or LOS.
Transmitter
The optical transmitter incorporates a 12-channel VCSEL
(Vertical Cavity Surface Emitting Laser) array, a 12-channel
input buffer and laser driver, diagnostic monitors, and
control and bias blocks. The transmitter is designed for
EN 60825 and CDRH eye safety compliance. The Tx Input
Buffer provides differential inputs presenting a nominal
differential input impedance of 100 Ohms. AC coupling
capacitors are located inside the CXP module and are not
required on the host board. For module control and inter-
rogation, the control interface incorporates a Two Wire
Serial (TWS) interface of clock and data signals.
Modules have monitors for VCSEL bias, light output power
(LOP), temperature, and power supply voltage implement-
ed; real-time results are available through the TWS interface.
Alarm thresholds are established for the monitored
attributes. Flags are set and interrupts generated when the
attributes are outside the thresholds.
Over the TWS interface, the user can, for individual
channels, control (flip) polarity of the differential inputs,
de-activate channels, disable the squelch function and
program input equalization levels to reduce the effect of
long PCB traces.
Flags are also set and interrupts generated for loss of input
signal (LOS) and transmitter fault conditions. All flags are
latched and will remain set even if the condition initiating
the latch clears and operation resumes. All interrupts can
be masked and flags are reset by reading the appropriate
flag register.
The optical output will AC squelch for loss of input signal
unless squelch is disabled. The input thresholds for the Tx
squelch are tied to Tx LOS thresholds which are informa-
tive only. See Tx LOS thresholds specification on page 6.
Fault detection or channel deactivation through the TWS
interface will disable the channel. Status, alarm and fault
information are available via the TWS interface. To reduce
the need for polling, the hardware interrupt signal is
provided to inform hosts of an assertion of an alarm, LOS
and/or Tx fault.
WARNING
CLASS 1M LASER PRODUCT: INVISIBLE LASER RADIATION, DO NOT VIEW DIRECTLY WITH OPTICAL INSTRUMENTS
CAUTION!
Viewing the laser output with certain optical instruments (for
example, eye loupes, magnifiers and microscopes) within a distance of
100 mm may pose an eye hazard.
CAUTION!
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.
Note: Standard used for classification: EN 60825-1:2007
INVISIBLE LASER RADIATION
DO NOT VIEW DIRECTLY
WITH OPTICAL INSTRUMENTS
CLASS 1M LASER PRODUCT
