CT-0155TSP-KB8L-E 2M 1550 nm DFB 80 km 2 Mb/s SFP Transceiver w. DDMI

Yes, it is specified for an 80 km single-mode link, but usable reach must be confirmed from the installed optical loss rather than distance alone. The minimum launch power of -5 dBm and receiver sensitivity of -34 dBm give a calculated minimum optical budget of 29 dB. That budget must cover fibre attenuation, connectors, splices, repair allowances, ageing and the engineer’s chosen operating margin. The receiver’s maximum input level is -3 dBm, so a short, low-loss test path driven near the 0 dBm maximum launch level may need at least 3 dB of attenuation to avoid overload.

No. It uses an SFP package, but its serial interface is 2 Mb/s NRZ for IEEE C37.94 or IEC 62843 rather than a conventional Ethernet physical interface. The host must provide 3.1 to 3.5 V power, an AC/AC differential transmit interface with a 400 to 1600 mV input swing, and receive circuitry compatible with a 0.4 to 1.3 V differential output. It should also implement TX_DISABLE, TX_FAULT, LOS and the two-wire I²C interface for identification and diagnostics. Mechanical fit alone is therefore insufficient; the host’s electrical interface and firmware must match the module.

The interface reports module temperature, supply voltage, laser bias current, transmitted optical power and received optical power through the A2h diagnostic memory, while serial identification is held at A0h. Listed accuracy is ±3°C for temperature, ±3% for voltage, ±10% for bias current and ±3 dB for both optical power readings. The stated accuracy ranges are -3 to +2 dBm for transmitted power and -30 to -3 dBm for received power, which do not span the full -5 to 0 dBm transmitter output or the -34 dBm receiver limit. Host software should therefore treat readings outside the listed monitoring ranges cautiously and use the alarm registers as operational indicators rather than precision measurement data.

Plan for separate transmitter and receiver current maxima of 200 mA and 100 mA respectively. A conservative combined allowance is therefore 300 mA; at the 3.5 V upper operating limit, this corresponds to about 1.05 W if both maxima occur together. The normal supply range is 3.1 to 3.5 V, while 6 V is an absolute maximum and not an operating target. Board design should keep VccT and VccR properly filtered and follow the recommended SFP interface arrangement, with local thermal analysis based on the enclosure and airflow.

Allow up to 300 ms for initialisation, including reset of TX_FAULT, after power is applied or the module is inserted. TX_DISABLE can assert within 10 µs and may take up to 1 ms to negate, while TX_FAULT can assert within 100 µs of a fault. Receiver LOS assertion and deassertion are each specified at up to 100 µs, and a TX_DISABLE reset pulse must be held for at least 10 µs. Firmware should therefore debounce status lines, respect the full start-up interval and avoid declaring a link failure before the timing limits have expired.

The module is rated for case operation from -40 to +85°C, with the same -40 to +85°C range listed for storage. It is RoHS compliant and lead-free, and the optical output is classified as a Class 1 laser product under IEC 60825-1 Ed.2:2007-03 and the stated FDA laser requirements. Its EMC design is intended to satisfy FCC Class B limits, with EN55022/CISPR22 also identified for equipment-level consideration. These statements do not replace qualification of the complete host, because enclosure design, PCB layout, grounding, cage design and other installed components determine final system compliance.

The module should be connected to 9/125 µm single-mode fibre through a duplex LC interface, using separate transmit and receive paths. Its transmitter uses a 1550 nm DFB laser with a centre-wavelength range of 1530 to 1570 nm, at least 10 dB extinction ratio, at least 30 dB side-mode suppression and no more than 1 nm spectral width at -20 dB. The receiver accepts wavelengths from 1100 to 1600 nm, but the intended paired link remains the specified 1550 nm single-mode design. This optical format is not a single-fibre bidirectional arrangement, so both LC channels and the correct Tx-to-Rx polarity are required.