4

TRXAG1SX

21737-0922 Rev.02. (web) 2013-07-04

Oplink Communications, Inc

18

19

3

TX DATA IN+

15

1µH coil or ferrite bead

(<0.2Ω series resistance)

0.1

TX DATA IN-

TX Disable

16

0.1

50Ω line

50Ω line

50Ω line

50Ω line

1, 9, 10, 11, 14, 17, 20

0.1

(100Ω to ground internally)

to 50Ω load

Vcc

3.3V

RX DATA OUT+

13

12

RX DATA OUT-

5

4

6

MOD_DEF(0)

MOD_DEF(1)

MOD_DEF(2)

LOS

to 50Ω load

8

R

2

TX Fault

RR

R

Vcc

3.3V

100

Application Notes

Example of SFP host board schematic

R: 4.7 to 10kΩ

CAP Values in µF

TRXAG1SX

and MOD_DEF(0) is TTL LOW. When the host system detects this

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. This device does not require clock stretching.

The serial data signal (SDA) is for serial data transfer. The host

uses SDA in conjunction with SCL to mark the start and 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 SFP MSA, and

SFF-8472, Rev. 9.4

Power supply and grounding: The power supply line should be

well-filtered. All 0.1μF power supply bypass capacitors should

be as close to the transceiver module as possible.

Electrical interface: All signal interfaces are compliant with

the SFP MSA specification. The high speed DATA interface is

differential AC-coupled internally 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 that should

be pulled up with a 4.7 - 10kΩ resistor on the host board.TX Fault

is latched per SFP MSA.

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),