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CT-CSFP-BX-20U
Compatible optical transceiver

CSFP 2-Channel BiDi 1490nm-TX/1310nm-RX 20km DOM Duplex LC/UPC SMF Optical Transceiver Module

Form Factor: SFP
Max Reach: 20KM
Interface Type: LC
Media: SM
Part number CT-CSFP-BX-20U

1.25G CSFP 1310/1550NM,1310/1490NM 20KM

Carritech Optics 1.25 Gbps Compact SFP BiDi Transceiver (20 km, 1310/1490 nm) is a dual-channel CSFP module designed for cost-efficient Gigabit Ethernet BX20 and FTTH deployments, featuring FP/DFB laser transmitters, PIN receivers, and full digital diagnostic monitoring.

This transceiver is a compatible alternative for the following manufacturer part numbers: (6)

AT-SPBD20DUAL-13 100-04622 CSFP-GE-FE-BXU1 3FE68720AA 3HE08313AA CSFP-BX1310-20-D

Quality assured Tested, compliant and backed by lifetime warranty.

Lifetime Warranty
FCC Mark
CE Mark
RoHS Compliant
ISO 9001
ISO 14001
Hardware compatibility

Popular hardware this transceiver is compatible with:

The hardware listed below is a selection of key popular equipment, not a complete compatibility list. This transceiver may also be compatible with many other hardware models. Contact us and we can check the exact hardware you need.

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Product information

CT-CSFP-BX-20U Details

Review the technical specifications, applications, features, delivery information and warranty coverage for this product.

Specifications

01

The 1.25Gbps 1310/1490nm Compact SFP (CSFP) Transceiver is a high-performance optical module designed for bi-directional data communication over single-mode fiber (SMF) up to 20 kilometers. Encased in a compact SFP form factor with an LC/UPC optical interface, it supports data rates of up to 1250Mbps and complies with the 1000Base-BX20 IEEE802.3ah standard. The module integrates a 1310nm FP laser for upstream transmission, a 1490nm DFB laser for downstream transmission, and a PIN photodetector for reliable performance. Its compliance with CSFP MSA and SFF-8472 standards ensures broad compatibility across networking equipment.

Operating on a single +3.3V power supply, the transceiver is energy-efficient with a power consumption of less than 1.5W. It is designed for commercial applications with a case operating temperature range of 0°C to 70°C. The module’s metal enclosure minimizes electromagnetic interference (EMI), ensuring stable and reliable operation in high-performance networks. RoHS compliance further underscores its environmentally responsible design.

The transceiver’s optical performance is optimized for reliability. The transmitter provides an average output power between -9dBm and -3dBm, with an extinction ratio of 8.2dB. The receiver sensitivity is rated at -19dBm, and the module includes advanced diagnostic features such as Loss of Signal (LOS) detection. The LOS output indicates link status or insufficient optical power, enhancing monitoring capabilities for operational stability.

Electrically, the module features a differential impedance of 100Ω and supports input and output swing differentials to facilitate integration with host systems. Digital diagnostics are accessible via a 2-wire serial interface, providing real-time insights into parameters like temperature, voltage, bias current, and optical power. Alarm and warning thresholds alert users to deviations from optimal operating conditions, ensuring reliability and performance.

In summary, the 1.25Gbps 1310/1490nm Compact SFP Transceiver is a robust and efficient solution for short to medium-range bi-directional optical communication. Its advanced optical and electrical capabilities, combined with compliance to industry standards, make it a valuable component for modern networking and telecommunications infrastructure.

This CSFP transceiver delivers 1.25 Gbps bidirectional links over up to 20 km of 9/125 µm single-mode fiber. It complies with CSFP MSA Option 2, IEEE 802.3ah 1000BASE-BX20, and SFF-8472, providing two independent bidirectional optical channels (Ch A and Ch B). The 20U version uses a 1310 nm FP laser for TX and 1490 nm PIN RX, while the 20D version uses a 1490 nm DFB laser for TX and 1310 nm PIN RX. Operating from a 3.3 V supply, it supports real-time digital diagnostic monitoring (DDM) and offers hot-pluggable deployment with LC/UPC interface.

Optical & Link Performance

Parameter Value Notes
Data rate 1.25 Gbps (TX/RX) IEEE 802.3ah BX20 compliant
Reach 20 km 9/125 µm SMF
TX wavelength 1310 nm (U) / 1490 nm (D) FP laser (1310), DFB laser (1490)
RX wavelength 1490 nm (U) / 1310 nm (D)
TX output power -9 to -3 dBm Average
Extinction ratio ≥8.2 dB
SMSR ≥30 dB (1490 nm DFB)
Spectral width ≤3.5 nm (1310 FP), ≤1 nm (1490 DFB)
RX sensitivity ≤-19 dBm BER ≤1×10⁻¹², ER = 8.2 dB, PRBS 2⁷-1
RX overload -3 dBm
LOS assert/de-assert -38 dBm / -22 dBm; hysteresis 0.5–6 dB LOS high = signal lost
Eye mask IEEE 802.3ah compliant Class 1 laser

Electrical & Environmental

Parameter Value Notes
Supply voltage 3.13–3.47 V (nom. 3.3 V)
Max supply current 450 mA (total for TX+RX)
Power supply noise ≤100 mVp-p (100 Hz–1 MHz)
Case temperature 0 °C to +70 °C Operating
Connector LC/UPC Pluggable
Form factor Compact SFP (CSFP, Option 2) Hot-pluggable, dual-channel
Diagnostics SFF-8472 DDM (Temp, Vcc, TxBias, TxPower, RxPower) I²C addresses A0h/A2h (Ch1), B0h/B2h (Ch2)
Control/Status Tx Disable, Tx Fault, LOS I²C accessible

Compliance

  • CSFP MSA Option 2, IEEE 802.3ah BX20, SFF-8472.
  • Class 1 laser (IEC/EN 60825-1/-2, FDA 21 CFR 1040.10/1040.11).
  • EMI/ESD: FCC Part 15 Class B, EN 55022 Class B, IEC/EN 61000-4-2.
  • Safety/EMC/RoHS: IEC/EN 60950 (UL), EN 61000-3, 2002/95/EC.

Applications

02
  • Gigabit Ethernet BX20 (IEEE 802.3ah) for metro and access networks.
  • FTTH point-to-point links using 1310/1490 nm optics.
  • Switch-to-switch and router/server interconnects.
  • Switched backplane connectivity in enterprise and telecom systems.

Features

03
  • Compact SFP (CSFP) dual-channel design enabling two BiDi links in one module.
  • 1310 nm FP / 1490 nm DFB laser options with PIN receiver for reliable bidirectional transmission.
  • Hot-pluggable footprint with LC/UPC connector for simplified deployment.
  • Digital Diagnostics Monitoring (DDM) via I²C with alarms and warnings.
  • RoHS compliant, 3.3 V single supply, 0–70 °C operating range.

Delivery

04

At Carritech, we pride ourselves on our exceptional service and commitment to meeting our customers’ needs. Our extensive range of SFP transceivers, including the CT-CSFP-BX-20U, is designed to cater to various requirements, ensuring that you receive the best solutions for your projects. We understand the importance of timely delivery, and our efficient processes are geared towards providing you with the products you need as quickly as possible. Our dedicated team works tirelessly to ensure that your orders are processed and dispatched promptly, so you can rely on us for swift and reliable service.

We recognise that every project is unique, and our flexible approach allows us to adapt to your specific needs. Whether you require immediate delivery or have more complex requirements, we are here to support you every step of the way. Our commitment to customer satisfaction means that we go above and beyond to ensure that you receive your SFP transceivers in a timely manner, without compromising on quality. Trust Carritech to deliver the solutions you need, when you need them.

Warranty

05

At Carritech Optics, we stand by the quality and reliability of our optical transceivers. That’s why we proudly offer a lifetime warranty on all products as a testament to our commitment to excellence and customer satisfaction.

What Does Our Lifetime Warranty Cover?

Our lifetime warranty provides comprehensive coverage for the entire lifecycle of your optical transceivers, ensuring you experience complete peace of mind when choosing Carritech Optics. The warranty covers:

  • Defects in Materials and Workmanship: If your product experiences any issues related to manufacturing or materials, we’ll repair or replace it free of charge.
  • Performance Assurance: Our optical transceivers are rigorously tested to meet industry standards, and we guarantee they’ll perform as expected in your network environment.

Easy Claims Process

Should you ever need to make a warranty claim, our team is here to assist you. Simply contact our support team with your product details, and we’ll guide you through a quick and hassle-free process to resolve the issue.

Your Network’s Performance, Guaranteed

Carritech Optics is dedicated to providing high-quality optical solutions that you can trust for the long haul. With our lifetime warranty, you can confidently invest in our products, knowing that we’re with you every step of the way.

Datasheet

06

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Manufacturer part number compatibility

This product is a fully compatible alternative to the following manufacturer part numbers

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CSFP 2-Channel BiDi 20km