SPT-P2T13V3-40D Dual 3G-SDI Transmitter Module Application Solutions

Note: This section provides engineering reference solutions and does not contain original datasheet specifications.

The SPT-P2T13V3-40D is a dual independent 3G-SDI transmitter SFP module operating at 1310nm over single-mode fiber up to 40km with dual TOSA optical outputs. It converts two SD-SDI/HD-SDI/3G-SDI electrical signals into optical signals, making it ideal for long-distance fiber transmission in broadcast video applications. Since this module is transmitter-only, the system requires a matching SDI receiver SFP module (dual receiver) to convert the optical signals back to BNC SDI outputs.

Standards Compliance: SMPTE 259M (SD-SDI), SMPTE 292M (HD-SDI), SMPTE 424M (3G-SDI), SMPTE 297-2006 optical interface standard.

Solution 1: Studio Dual 3G-SDI Fiber Extension (40km Long-Distance Signal Transmission)

Application Scenario

In TV studios and broadcast truck systems, cameras output two 3G-SDI signals that need to be transmitted to a secondary control room within 40km. Traditional 75Ω coaxial cables can only transmit 3G-SDI signals for about 100 meters, while fiber optics enable long-distance, lossless, low-latency transmission.

System Architecture

1. Transmitter Main Board: Equipped with SPT-P2T13V3-40D Dual Transmitter SFP Module
   • Two 3G-SDI BNC outputs from cameras pass through on-board SDI drivers, outputting PECL differential signals to the module's TD1± and TD2± inputs;
   • Host FPGA/MCU controls TX1_DIS and TX2_DIS to switch lasers on/off, and reads TX1_FAULT and TX2_FAULT status;
   • I2C interface provides real-time DDM monitoring of module temperature, laser power, and bias current, reporting to the network management system;
   • The module's dual LC optical ports output two optical signals, connected via two single-mode OS2 fibers.
2. Fiber Link: Single-mode OS2 fiber, maximum distance 40km, LC-LC patch cord connection
3. Receiver End: Dual 3G-SDI Receiver SFP Module Board
   • Converts received optical signals back to two differential SDI electrical signals;
   • SDI driver chips convert to BNC 75Ω 3G-SDI output, connecting to switchers, waveform monitors, and displays.

Solution Advantages

1. Dual channels integrated in a single SFP housing, saving one SFP cage compared to two single-channel SFPs, reducing board BOM costs;
2. Native support for SDI pathological test patterns, meeting broadcast equipment network access testing standards;
3. DDM real-time monitoring of optical module status enables remote预警 of laser aging and temperature threshold violations;
4. Metal housing with low EMI, providing interference resistance in complex studio electromagnetic environments;
5. Low latency with completely uncompressed SDI transparent transmission, ideal for live production.

Precautions

1. The transmitter is a pure transmit module; the receiver end must purchase a corresponding dual SDI receiver module - this module cannot connect to itself;
2. 40km transmission requires fiber loss budgeting with optical power margin to ensure received power does not fall below receiver sensitivity;
3. Studio equipment should have proper system grounding to reduce EMI interference.

Solution 2: Outdoor Live Broadcast Dual-Camera Signal Backhaul

Scenario Description

At outdoor events and evening galas, two cameras output two 3G-SDI signals. The现场 location is several kilometers to 40km from the broadcast control room. The现场 equipment chassis houses an SDI optical transmitter board with SPT-P2T13V3-40D, transmitting two video channels back to the broadcast control room via fiber.

System Key Points

1. Field end: Camera SDI signal → board SDI driver → SPT-P2T13V3-40D converts to optical signal;
2. Fiber deployment uses outdoor single-mode optical cable;
3. Control room receiver board recovers two SDI signals for the director's switcher;
4. Remote operations: I2C reads DDM data to monitor laser operating status; TX_Fault triggers remote alarms;
5. Environmental constraints: This module is commercial grade 0-70°C; outdoor enclosures must implement temperature-controlled cooling, and ambient temperature must not exceed 0-70°C. High-temperature environments should add temperature-controlled fans.

Solution 3: Customized 2-Channel SDI Fiber Output Board (OEM Board Reference Design)

Equipment manufacturers developing 2-channel SDI optical transmitter boards can directly select the SPT-P2T13V3-40D SFP module, eliminating the need to develop TOSA optical paths independently, thereby shortening development cycles.

Board Hardware Design Key Points

1. SFP-MSA standard cage, supporting 20-pin gold fingers;
2. Hardware circuits follow the tutorial chapter for pull-up resistors: TX_FAULT open-collector pull-up, I2C bus SDA/SCL pull-ups;
3. SDI input section: SDI receiver outputs PECL differential signals, directly connecting to TD1± and TD2±. The module has internal AC coupling; do not add additional DC blocking capacitors on the board; differential traces must strictly maintain 100Ω differential impedance;
4. FPGA logic: Wait 300ms after power-on for module initialization before accessing I2C; software can control TX_DIS to enable/disable both lasers; read TX_FAULT status; read DDM parameters and report to upper-level management software;
5. 3.3V power supply with maximum current of 500mA; power design should include adequate margin.

Software Function Recommendations

1. Read 0xA0 to obtain module model and serial number;
2. Periodically read 0xA2 for temperature, voltage, laser bias current, and transmit optical power;
3. Threshold alarms: [Engineering recommended warning thresholds (not mandatory datasheet thresholds): System should warn when temperature exceeds 65°C; maximum allowable operating case temperature is 70°C]; low optical power warning; immediate reporting of TX_Fault.

System General Constraints and Limitations

1. Module positioning: Dual transmitter SFP with no optical receive channel, cannot achieve bidirectional transceiver functionality;
2. Supported data rate range: 50Mbps-2.97Gbps, supporting SD-SDI (270Mbps), HD-SDI (1.485Gbps), 3G-SDI (2.97Gbps); does not support 6G/12G-SDI;
3. Operating temperature: Commercial grade 0-70°C; contact Sopto for custom wide-temperature industrial grade;
4. Laser safety Class I; equipment enclosure design must ensure users cannot directly view the optical port;
5. RoHS compliant, suitable for domestic broadcast equipment market access.

Supporting Equipment Selection Reference List

Customization: For special temperatures or wavelengths, contact Sopto original manufacturer at info@sopto.com.cn for custom development.