TRXA48M Datasheet, PDF (4/5 Pages) OPLINK Communications Inc. – Multi-rate OC-48/STM-16 SFP Transceivers with Digital Diagnostics

Example of SFP host board schematic
1μH coil or ferrite bead
(<0.2Ω series resistance)
Vcc
3.3V
+ ₁₀
0.1
16
0.1
2
8
15
+ ₁₀
0.1
4
TRXA48M 5
TX Disable
TX DATA IN+
3
6
100
18
13
TX DATA IN-
19
12
1, 9, 10, 11, 14, 17, 20
TRXA48M Single Mode
Vcc
3.3V
RRR R
TX Fault
LOS
MOD_DEF(2)
MOD_DEF(1)
MOD_DEF(0)
(Internally Grounded)
RX DATA OUT+
to 50Ω load
RX DATA OUT-
to 50Ω load
R: 4.7 to 10kΩ
Application Notes
Electrical interface: All signal interfaces are compliant with
the SFP MSA specification. The high speed DATA interface
is differential AC-coupled internally with 0.1μF and can be
directly connected to a 3.3V SERDES IC. All low speed control
and sense output signals are open collector TTL compatible
and should be pulled up with a 4.7 - 10kΩ resistor on the
host board
Loss of Signal (LOS): The Loss of Signal circuit monitors
the level of the incoming optical signal and generates a logic
HIGH when an insufficient photocurrent is produced.
TX_Fault: The output indicates LOW when the transmitter
is operating normally, and HIGH with a laser fault including
laser end-of-life. TX Fault is an open collector/drain output
and should be pulled up with a 4.7 - 10kΩ resistor on the
host board. TX Fault in non-latching (automatically deasserts
when fault goes away).
TX_Disable: When the TX Disable pin is at logic HIGH, the
transmitter optical output is disabled (less than -45dBm).
Serial Identification and Monitoring: The module
definition of SFP is indicated by the three module definition
pins, MOD_DEF(0), MOD_DEF(1) and MOD_DEF(2).
Upon power up, MOD_DEF(1:2) appear as NC (no connection),
and MOD_DEF(0) is TTL LOW. When the host system detects
this condition, it activates the serial protocol (standard
two-wire I²C serial interface) and generates the serial clock
signal (SCL). The positive edge clocks data into the EEPROM
segments of the SFP that are not write protected, and the
negative edge clocks data from the SFP.
The serial data signal (SDA) is for serial data transfer. The
host uses SDA in conjunction with SCL to mark the startand
end of serial protocol activation. The supported monitoring
functions are internal temperature, supply voltage, bias
current, transmitter power, average receiver signal, all alarms
and warnings and software monitoring of TX Fault/LOS. The
device is internally calibrated.
The data transfer protocol and the details of the mandatory
and vendor specific data structures are defined in the SFPMSA,
and SFF-8472, Rev. 9.4
Power supply and grounding: The power supply line
shouldbe well-filtered. All 0.1μF power supply bypass
capacitors should be as close to the transceiver module
as possible.
Laser Safety
Laser Safety: All transceivers are Class I Laser
products per FDA/CDRH and IEC-60825 stan-
dards. They must be operated under specified
operating conditions.
Oplink Communications, Inc.
DATE OF MANUFACTURE:
This product complies with
21 CFR 1040.10 and 1040.11
Meets Class I Laser Safety Requirements
Oplink Communications, Inc.
4
RevC-NP.2008.09.09