HFBR-0570 Avago Technologies US Inc., HFBR-0570 Datasheet - Page 3

• Manufacturer Part Number: HFBR-0570
• Description: Fiber Optics, Evaluation Kit
• Manufacturer: Avago Technologies US Inc.

Specifications of HFBR-0570

• Silicon Core Number: HFBR-5720L, HFBR-5720LP, HFBR-5720AL, HFBR-5720ALP
• Kit Contents: Evaluation PC Board, Associated Technical Literature
• Kit Features: For SFP Fiber Channel Applications
• Main Purpose: Interface, Fiber Optics
• Embedded: No
• Utilized Ic / Part: HFBR-5720
• Primary Attributes: SFP Fibre Channel Applications
• Secondary Attributes: Small Form Factor Pluggable (SFP)
• Tool / Board Applications: Optical Transceivers
• Rohs Compliant: Yes
• Operating Voltage: 3.3 V
• Description/function: Fiber Optic Kit
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 20 C
• Development Tool Type: Hardware / Software - Eval/Demo Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: HFBR-5720x
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Figure 2. Connection diagram of module printed circuit board.
Transmitter Section
The transmitter section includes
the transmitter optical
subassembly (TOSA) and laser
driver circuitry. The TOSA,
containing an 850 nm VCSEL
(Vertical Cavity Surface Emitting
Laser) light source, is located at
the optical interface and mates
with the LC optical connector.
The TOSA is driven by a custom
silicon IC, which converts
differential logic signals into an
analog laser diode drive current.
This Tx driver circuit regulates
the optical power at a constant
level provided the data pattern is
valid 8B/10B balanced code.
Tx Disable
The HFBR-5720AL/ALP accepts a
transmit disable control signal
input which shuts down the
transmitter. A high signal
implements this function while a
low signal allows normal laser
operation. In the event of a fault
(e.g., eye safety circuit activated),
cycling this control signal resets
3
20
19
18
17
16
15
14
13
12
11
V
TD–
TD+
V
V
V
V
RD+
RD–
V
EE
EE
CC
CC
EE
EE
T
T
R
R
T
R
TOP OF BOARD
the module as depicted in
Figure 6. The Tx Disable control
should be actuated upon
initialization of the module.
Tx Fault
The HFBR-5720AL/ALP module
features a transmit fault control
signal output which when high
indicates a laser transmit fault
has occurred and when low
indicates normal laser operation.
A transmitter fault condition can
be caused by deviations from the
recommended module operating
conditions or by violation of eye
safety conditions. A fault is
cleared by cycling the Tx Disable
control input.
Eye Safety Circuit
For an optical transmitter device
to be eye-safe in the event of a
single fault failure, the
transmitter will either maintain
normal eye-safe operation or be
disabled. In the event of an eye
safety fault, the VCSEL will be
disabled.
(AS VIEWED THROUGH TOP OF BOARD)
10
1
2
3
4
5
6
7
8
9
V
TxFAULT
Tx DISABLE
MOD-DEF(2)
MOD-DEF(1)
MOD-DEF(0)
RATE SELECT
LOS
V
V
EE
EE
EE
BOTTOM OF BOARD
T
R
R
Receiver Section
The receiver section includes the
receiver optical subassembly
(ROSA) and amplification/
quantization circuitry. The ROSA,
containing a PIN photodiode and
custom transimpedance
preamplifier, is located at the
optical interface and mates with
the LC optical connector. The
ROSA is mated to a custom IC
that provides post-amplification
and quantization. This circuit also
includes a loss of signal (LOS)
detection circuit which provides
an open collector logic high
output in the absence of a usable
input optical signal level.
Loss of Signal
The Loss of Signal (LOS) output
indicates that the optical input
signal to the receiver does not
meet the minimum detectable
level for Fibre Channel compliant
signals. When LOS is high it
indicates loss of signal. When
LOS is low it indicates normal
operation. The Loss of Signal