1.25G SFP EX 1550nm 40KM LC SMF Fiber Optic Transceiver

Module Block Diagram

1. Pin Definitions

2. Absolute Maximum Ratings

3. Optical Characteristics

Notes:
1. Class 1 Laser Safety per FDA/CDRH and IEC-825-1 regulations.
2. With worst-case extinction ratio. Measured with a PRBS 223-1 test pattern, @1.25Gb/s, BER<10-12 .
3. Jitter added by receiver (peak to peak). Measured at –18.0dBm average Rx sensitivity, PRBS 223-1 test pattern.

4. Pin Descriptions

Notes:
1. Circuit ground is internally isolated from chassis ground.

2. TFAULT is an open collector/drain output, which should be pulled up with a 4.7k – 10k Ohms resistor on the host board if intended
for use. Pull up voltage should be between 2.0V to Vcc + 0.3V. A high output indicates a transmitter fault caused by either the
TX bias current or the TX output power exceeding the preset alarm thresholds. A low output indicates normal operation. In the
low state, the output is pulled to <0.8V.

3. Laser output disabled on TDIS>2.0V or open, enabled on TDIS<0.8V.

4. Should be pulled up with 4.7k – 10kohms on host board to a voltage between 2.0V and 3.6V. MOD_DEF (0) pulls line low to
indicate module is plugged in.

5. LOS is open collector output. It should be pulled up with 4.7k – 10 kohms on host board to a voltage between 2.0V and 3.6V.
Logic 0 indicates normal operation; logic 1 indicates loss of signal.

5. Typical Interface Circuit

6. Electrical Interface Characteristics

Notes:
1. Connected directly to TX data input pins. AC coupled thereafter.
2. Or open circuit.
3. Into 100 ohms differential termination.
4. 20 – 80 %
5. Loss of Signal is LVTTL. Logic 0 indicates normal operation; logic 1 indicates no signal detected.
6. Receiver sensitivity is compliant with power supply sinusoidal modulation of 20 Hz to 1.5 MHz up to specified value applied
through the recommended power supply filtering network.

7. Digital Diagnostic Functions

ETU-LINK ES5512-3LCD40 transceivers support the 2-wire serial communication protocol as defined in the SFP MSA1. It is very closely related to the EEPROM defined in the GBIC standard, with the same electrical specifications.

The standard SFP serial ID provides access to identification information that describes the transceiver’s capabilities, standard interfaces, manufacturer, and other information.

Additionally, ETU-LINK SFP transceivers provide a unique enhanced digital diagnostic monitoring interface, which allows real-time access to device operating parameters such as transceiver temperature, laser bias current, transmitted optical power, and received optical power and transceiver supply voltage. It also defines a sophisticated system of alarm and warning flags, which alerts end-users when particular operating parameters are outside of a factory set normal range.

The SFP MSA defines a 256-byte memory map in EEPROM that is accessible over a 2-wire serial interface at the 8 bit address 1010000X (A0h). The digital diagnostic monitoring interface makes use of the 8 bit address 1010001X (A2h), so the originally defined serial ID memory map remains unchanged. The interface is identical to, and is thus fully backward compatible with both the GBIC Specification and the SFP Multi Source Agreement.

The operating and diagnostics information is monitored and reported by a Digital Diagnostics Transceiver Controller (DDTC) inside the transceiver, which is accessed through a 2-wire serial interface. When the serial protocol is activated, the serial clock signal (SCL, Mod Def 1) is generated by the host. The positive edge clocks data into the SFP transceiver into those segments of the E2PROM that are not write-protected. The negative edge clocks data from the SFP transceiver. The serial data signal (SDA, Mod Def 2) is bi-directional for serial data transfer.

The host uses SDA in conjunction with SCL to mark the start and end of serial protocol activation. The memories are organized as a series of 8-bit data words that can be addressed individually or sequentially.

8. Mechanical Specifications