Specifications
The CT-SFP-BX-80U and CT-SFP-BX-80D are advanced bi-directional (BIDI) SFP optical transceivers designed for 1.25Gbps data transmission over single-mode fiber (SMF) distances of up to 80 kilometers. The CT-SFP-BX-80U employs a 1490nm DFB laser and a 1550nm PIN photodetector, while the CT-SFP-BX-80D uses a 1550nm DFB laser and a 1490nm PIN photodetector. Packaged in a compact SFP form factor with LC connectors, these modules are ideal for Ethernet, Telecom, and Fiber Channel applications. Fully compliant with IEC-60825 laser safety standards and RoHS regulations, they deliver reliable performance in demanding environments.
Key features include operation within a wide temperature range (-40°C to +85°C for industrial grade, 0°C to +70°C for commercial grade) and compatibility with a +3.3V power supply. The modules boast excellent optical performance, including high extinction ratios, precise wavelength control (1490nm/1550nm), and low EMI. Robust electrical characteristics such as LVPECL-compatible interfaces and ESD protection make these transceivers suitable for long-distance and high-speed optical communication networks.
These BiDi SFP modules are optimized for Ethernet, Fibre Channel, and telecom applications where single-fiber operation up to 80 km is required. Operating from a single +3.3 V supply, they feature LVPECL-compatible I/O, low EMI design, and strong ESD protection. The devices meet IEC-60825 laser safety and RoHS compliance standards.
Absolute Maximum Ratings
| Parameter | Symbol | Min | Max | Units |
|---|---|---|---|---|
| Storage temperature | Tst | −40 | +85 | °C |
| Supply voltage | Vcc | 0 | +3.6 | V |
| Operating relative humidity | RH | 5 | 95 | % |
Operating Conditions
| Parameter | Symbol | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Supply voltage | Vcc | 3.15 | 3.3 | 3.45 | V |
| Case temperature (Commercial) | Tc | 0 | — | +70 | °C |
| Case temperature (Industrial) | — | −40 | — | +85 | °C |
| Power dissipation | — | — | — | 1 | W |
| Data rate | — | — | 1.25 | — | Gbps |
Optical Characteristics (0 °C to +70 °C, Vcc = 3.3 V)
Transmitter
| Parameter | Variant | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Center wavelength | Tx 1490 | 1480 | 1490 | 1500 | nm |
| Center wavelength | Tx 1550 | 1540 | 1550 | 1560 | nm |
| RMS spectral width | Tx 1490 / Tx 1550 | — | — | 1 | nm |
| Average output power | Tx 1490 / Tx 1550 | 0 | — | +5 | dBm |
| Extinction ratio | — | 10 | — | 15 | dB |
| Rise/fall time (20–80%) | — | — | — | 0.26 | ns |
| Total jitter | — | — | — | 0.43 | UI |
| Optical eye: IEEE 802.3z and ANSI Fibre Channel compatible. |
Receiver
| Parameter | Variant | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Center wavelength | Rx 1550 | 1500 | 1550 | 1600 | nm |
| Center wavelength | Rx 1490 | 1440 | 1490 | 1540 | nm |
| Sensitivity (Rsen) | — | — | — | −24 | dBm |
| Overload (Rov) | — | −3 | — | — | dBm |
| Return loss | — | 12 | — | — | dB |
| LOS assert (LOSA) | — | −36 | — | — | dBm |
| LOS de-assert (LOSD) | — | — | — | −24 | dBm |
| LOS hysteresis | — | 0.5 | — | 5 | dB |
BiDi pair mapping
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CT-SFP-BX-80U: 1490 nm DFB Tx / 1550 nm PIN Rx
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CT-SFP-BX-80D: 1550 nm DFB Tx / 1490 nm PIN Rx.
Electrical Characteristics (0 °C to +70 °C, Vcc = 3.3 V)
Transmitter I/O
| Parameter | Symbol | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Input differential impedance | Zin | 90 | 100 | 110 | Ω |
| Data input swing (diff.) | Vin | 500 | — | 2400 | mV |
| TX Disable — High (disable) | — | 2.0 | — | Vcc | V |
| TX Disable — Low (enable) | — | 0 | — | 0.8 | V |
| TX Fault — Assert | — | 2.0 | — | Vcc | V |
| TX Fault — De-assert | — | 0 | — | 0.8 | V |
Receiver I/O
| Parameter | Symbol | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Output differential impedance | Zout | — | 100 | — | Ω |
| Data output swing (diff.) | Vout | 370 | — | 2000 | mV |
| Rx_LOS — Assert | — | 2.0 | — | Vcc | V |
| Rx_LOS — De-assert | — | 0 | — | 0.8 | V |
EEPROM & Pins (summary)
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EEPROM (A0h): SFP identifier, LC connector, 1.25 Gbps nominal BR, LOS/TX_DISABLE/TX_FAULT functions, wavelength codes for 1490/1550 nm, vendor fields.
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Key pins: TX Disable (input with pull-up), TX Fault (open collector), LOS (open collector), MOD-DEF[0:2] for 2-wire serial ID. TD± and RD± are AC-coupled 100 Ω differential pairs.