AFCT-5016Z AVAGO [AVAGO TECHNOLOGIES LIMITED], AFCT-5016Z Datasheet - Page 3

• Manufacturer Part Number: AFCT-5016Z
• Description: 10Gb Ethernet, 850 nm, 10GBASE-SR, SFP+ Transceiver
• Manufacturer: AVAGO [AVAGO TECHNOLOGIES LIMITED]

Transmitter Section
The transmitter section includes the Transmitter Opti-
cal Sub-Assembly (TOSA) and laser driver circuitry. The
TOSA, containing an Avago designed and manufactured
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 an
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 con-
stant level provided the incoming data pattern is DC bal-
anced.
Transmit Disable (TX_DISABLE)
The AFBR-700SDZ accepts an LVTTL compatible trans-
mit disable control signal input which shuts down the
transmitter optical output. A high signal implements this
function while a low signal allows normal transceiver op-
eration. In the event of a fault (e.g. eye safety circuit ac-
tivated), cycling this control signal resets the module as
depicted in Figure 6. An internal pull up resistor disables
the transceiver transmitter until the host pulls the input
low. TX_DISABLE can also be asserted via the two-wire
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 (contact 3) to control transmitter
operation.
Figure 1. Transceiver functional diagram
3
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).
CIRCUITRY
DRIVER &
SAFETY
LASER
ELECTRICAL INTERFACE
RD+ (RECEIVE DATA)
RD– (RECEIVE DATA)
RX_LOS
RS0
RS1
SDA
SCL
MOD-ABS
TX_DISABLE
TD+ (TRANSMIT DATA)
TD– (TRANSMIT DATA)
TX_FAULT