AFBR-57R5APZ Avago Technologies US Inc., AFBR-57R5APZ Datasheet - Page 3

• Manufacturer Part Number: AFBR-57R5APZ
• Description: TXRX OPT SFP 4/2/1GBD 850NM
• Manufacturer: Avago Technologies US Inc.

Specifications of AFBR-57R5APZ

• Data Rate: 4.25GBd
• Wavelength: 850nm
• Voltage - Supply: 3.3V
• Connector Type: LC Duplex
• Mounting Type: SFP
• Function: Digital Diagnostic SFP, supports high-speed serial links over multimode optical fiber.
• Product: Transceiver
• Maximum Rise Time: 0.09 ns/0.15 ns
• Maximum Fall Time: 0.09 ns/0.15 ns
• Pulse Width Distortion: 0.06 ns (Max)/0.062 ns (Max)
• Operating Supply Voltage: 2.97 V to 3.63 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 10 C
• Package / Case: SFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With: Multimode Glass
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 516-1987

3
Figure 1. Transceiver functional diagram.
Transmitter Section
The transmitter section includes consists of the Transmit-
ter 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 IC which uses the
incoming differential high speed logic signal to modulate
the laser diode driver current. This Tx laser driver circuit
regulates the optical power at a constant level provided
the incoming data pattern is dc balanced (8B/10B code,
for example).
Transmit Disable (Tx_Disable)
The AFBR-57R5APZ accepts a TTL and CMOS compat-
ible transmit disable control signal input (pin 3) which
shuts down the transmitter optical output. A high signal
implements this function while a low signal allows
normal transceiver operation. In the event of a fault (e.g.
eye safety circuit activated), cycling this control signal
resets the module as depicted in Figure 4. An internal
pull up resistor disables the transceiver transmitter until
the host pulls the input low. Host systems should allow
a 10 ms interval between successive assertions of this
control signal. Tx_Disable can also be asserted via the
two-wire serial interface (address A2h, byte 110, bit 6)
and monitored (address A2h, byte 110, bit 7).
The contents of A2h, byte 110, bit 6 are logic OR’d with
hardware Tx_Disable (pin 3) to control transmitter
operation.
OPTICAL INTERFACE
LIGHT FROM FIBER
LIGHT TO FIBER
RECEIVER
TRANSMITTER
PHOTO-DETECTOR
VCSEL
CONTROLLER & MEMORY
AMPLIFICATION
& QUANTIZATION
Transmit Fault (Tx_Fault)
A catastrophic laser fault will activate the transmitter
signal, TX_FAULT, and disable the laser. This signal is
an open collector output (pull-up required on the host
board). A low signal indicates normal laser operation
and a high signal indicates a fault. The TX_FAULT will
be latched high when a laser fault occurs and is cleared
by toggling the TX_DISABLE input or power cycling the
transceiver. The transmitter fault condition can also be
monitored via the two-wire serial interface (address A2,
byte 110, bit 2).
Eye Safety Circuit
The AFBR-57R5APZ provides Class 1 (single fault tolerant)
eye safety by design and has been tested for compliance
with the requirements listed in Table 1. The eye safety
circuit continuously monitors the optical output power
level and will disable the transmitter upon detecting an
unsafe condition beyond the scope of Class 1 certifica-
tion. Such unsafe conditions can be due to inputs from
the host board (Vcc fluctuation, unbalanced code) or a
fault within the transceiver.
Receiver Section
The receiver section includes the Receiver Optical Sub-
Assembly (ROSA) and the amplification/quantization
circuitry. The ROSA, containing a PIN photodiode and
custom transimpedance amplifier, is located at the
optical interface and mates with the LC optical connector.
The ROSA output is fed to a custom IC that provides post-
amplification and quantization.
CIRCUITRY
DRIVER &
SAFETY
LASER
RD+ (RECEIVE DATA)
RD– (RECEIVE DATA)
Rx LOSS OF SIGNAL
MOD-DEF2 (SDA)
MOD-DEF1 (SCL)
MOD-DEF0
TX_DISABLE
TD+ (TRANSMIT DATA)
TD– (TRANSMIT DATA)
TX_FAULT
ELECTRICAL INTERFACE