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The LINK-PP LQD-M85400-SR4C is a high-performance 400G QSFP-DD SR4 optical transceiver engineered for high-density data center links. Operating over 850nm multimode fiber (MMF), it converts an 8x50G PAM4 (400GAUI-8) electrical interface into 4x100G optical channels. Compliant with IEEE 802.3db, IEEE 802.3cd, and CMIS 5.2 standards, it consumes under 8W with low-latency retimed performance.
| LINK-PP Part Number | LQD-M85400-SR4C | Vendor Name | LINK-PP |
| Form Factor | QSFP-DD | Max Data Rate | 425Gbps |
| Connector | MPO-12/APC | Media | MMF |
| Wavelength | 850nm | Max Cable Distance | 30m@OM3/50m@OM4 |
| Transmitter Type | VCSEL | Receiver Type | PIN |
| Modulation (Electrical) | 8x50G-PAM4 | Modulation (Optical) | 4x100G-PAM4 |
| DDM/DOM | Supported | Operating Temperature range | 0°C to +70°C |
| Protocols | QSFP-DD MSA, CMIS Rev5.0, IEEE 802.3df-2024 | Warranty | 5 Years |
The LINK-PP LQD-M85400-SR4C features integrated 4-channel VCSEL and PIN arrays, an MPO-12/APC optical interface, and sub-8W power consumption across 0°C to 70°C. Fully compliant with CMIS 5.2 and QSFP-DD MSA Type 2 specifications, it delivers robust, energy-efficient 400GE connectivity for modern networks.
The LINK-PP LQD-M85400-SR4C is a hot-pluggable optical transceiver module designed for 400 Gigabit Ethernet applications, offering seamless interoperability, low power dissipation, and high port density for next-generation enterprise leaf-spine switch architectures.
Designed for demanding telecom and data center environments, the LQD-M85400-SR4C delivers reliable 400G aggregation for MAN core networks and cloud facilities, facilitating low-latency throughput, breakout versatility, and scalable bandwidth expansion.
Utilizing a nominal 850nm wavelength VCSEL transmitter array, the LQD-M85400-SR4C optical module ensures excellent spectral purity, minimal dispersion penalty, and stable 53.125 GBd PAM4 optical signal transmission across multimode fibers.
The LQD-M85400-SR4C transceiver supports short-reach transmission distances up to 30 meters over OM3 and 50 meters over OM4 multimode fiber, providing a cost-effective, high-speed interconnect solution for intra-datacenter server racks.
Equipped with an industry-standard MPO-12/APC optical receptacle, the LQD-M85400-SR4C module minimizes optical return loss, optimizes fiber core alignment, and enables rapid parallel multi-fiber patching in ultra-dense cloud network cabling environments.
Featuring integrated Digital Optical Monitoring (DOM) via CMIS 5.2, the LQD-M85400-SR4C allows network engineers to monitor real-time operating parameters, including laser bias current, optical power levels, module temperature, and supply voltage.
The LINK-PP LQD-M85400-SR4C undergoes comprehensive qualification and holds international safety and environmental certifications, including CE, FCC, UKCA, UL, and REACH, verifying uncompromising quality and global regulatory adherence.
Every LQD-M85400-SR4C optical transceiver is subjected to an exhaustive quality testing program, validating signal integrity, parametric thresholds, and long-term durability to eliminate early network failure risks.
Fully compliant with RoHS, REACH, CE, and FCC directives, the LQD-M85400-SR4C meets rigorous electromagnetic compatibility and environmental protection benchmarks required for global tier-one data center deployments.
Tested extensively across mainstream network switches and routers, the LQD-M85400-SR4C ensures seamless multi-vendor compatibility, protocol stability, and hassle-free plug-and-play installation in diverse 400GE enterprise networking infrastructures.
Our state-of-the-art laboratory testing protocol guarantees that each QSFP-DD module delivers flawless transmission performance, superior thermal stability, and strict industry standard adherence.
Validates central 850nm wavelength accuracy and verifies RMS spectral width under 0.6nm.
Evaluates PAM4 optical eye clarity, extinction ratio, and TDECQ parameters for signal integrity.
Confirms pre-FEC BER compliance below 2.4E-4, guaranteeing error-free packet throughput under heavy load.
Assesses continuous commercial 0°C to 70°C case temperature performance under extreme thermal conditions.
Each LINK-PP LQD-M85400-SR4C transceiver is packaged with specialized protective materials and shipped through expedited logistics channels to ensure safe, on-time worldwide delivery.
Shielded inside ESD-safe clamshell trays to prevent electrostatic discharge damage during transit.
Reinforced outer cartons with custom cushioning absorb physical impacts during shipping.
Optimized inventory management enables rapid order processing and immediate warehouse dispatch.
Partnered with premier international carriers for dependable, trackable worldwide express delivery.
The LINK-PP LQD-M85400-SR4C features a hot-swappable QSFP-DD interface for straightforward installation in switch cages. Simply align the module, insert firmly until latched, and connect an MPO-12/APC cable to achieve instant 400G optical connectivity.
LINK-PP provides professional technical support, including pre-sales consultation, compatibility verification, and post-deployment troubleshooting to ensure smooth network operation.
Professional technical guidance to help customers select the most suitable LQD-M85400-SR4C modules based on network architecture and application requirements.
Compatibility checks and validation to ensure seamless operation with Cisco switches and other supported networking platforms.
Step-by-step support for installation, configuration, and initial deployment to ensure stable and correct operation.
Ongoing technical support throughout the product lifecycle to ensure reliable performance in enterprise and carrier-grade networks.
LINK-PP provides after-sales support for the smooth deployment and reliable operation of the optical modules.
15-day no-reason return and refund
Free replacement for dead-on-arrival (DOA) or defective items within the initial period
Free repair services for manufacturing defects throughout the warranty period
Warranty exclusions and conditions apply
Compatible | LINK-PP | LINK-PP | LINK-PP | LINK-PP |
Data Rate (Max) | 425Gbps | 425Gbps | 425Gbps (4x 106.25Gbps) | 425Gbps |
Wavelength | 850nm | 1310nm | 1310nm | 1310nm |
Connector | MPO-12/APC | MPO-12/APC | MPO-12/APC | MPO-12/APC |
Cable Distance (Max) | 30m | 500m | 10km | 500m |
Cable Type | MMF | SMF | SMF | SMF |
Operating Temperature | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C |
Form Factor | QSFP-DD | QSFP-DD | QSFP-DD | QSFP-DD |
Transmitter Type | VCSEL | DFB | EML | |
Receiver Type | PIN | PIN | PIN | PIN |
Modulation (Electrical) | 8x50G-PAM4 | 8x50G-PAM4 | 8x50G-PAM4 | |
Modulation (Optical) | 4x100G-PAM4 | 4x100G-PAM4 | 4x100G-PAM4 | |
DDM/DOM | Supported | Supported | Supported | Supported |
Protocols | QSFP-DD MSA, CMIS Rev5.0, IEEE 802.3df-2024 | QSFP-DD MSA, IEEE 802.3bs, CMIS 4.1 | QSFP-DD MSA HW Rev 5.1, QSFP-DD, CMIS Rev 5.0, IEEE 802.3cu, IEEE 802.3bs | QSFP-DD MSA HW Rev 5.1, QSFP-DD CMIS Rev 5.0, IEEE 802.3bs |
Warranty | 5 Years | 5 Years | 5 Years | 5 Years |
| Pictures | ID# | Description | Price | Stock | Add to Cart |
Q: What exact fiber cabling do I need to patch into this module for a 50-meter run? By S***a on 2026-08-29
A: You’ll need an MPO-12/APC (Angled Physical Contact) multimode fiber (MMF) patch cable. For a full 50-meter transmission distance, OM4 MMF is required. If you're utilizing existing OM3 fiber infrastructure, the maximum supported transmission distance will be limited to 30 meters. By admin on 2026-08-29
Q: We run a mixed environment of Cisco Nexus and Arista switches. Will these 400GBASE-SR4 modules play nice with both without throwing unsupported transceiver errors? By E***r on 2026-07-21
A: Absolutely! The LQD-M85400-SR4C is fully OEM compatible and tested extensively with Cisco, Arista, and other major brands. It supports CMIS 5.2, ensuring plug-and-play interoperability and accurate real-time DOM readings across your entire spine-leaf architecture. By admin on 2026-07-21
Q: Our data center is planning a major upgrade and we need around 100 pieces of these QSFP-DD optics. Do you guys offer volume discounts for batch deployments? By L***a on 2026-03-30
A: Yes, we definitely do! While the single-unit price is highly competitive, we offer tiered wholesale pricing designed for massive batch deployments. You can see automatic price drops starting at 10+ and 100+ units. Feel free to reach out to our sales engineering team for a custom enterprise quote. By admin on 2026-03-30
Q: We have some outdoor telecom cabinets that get pretty hot. Does this 400G module support industrial wide-temperature ranges, or is it strictly for indoor use? By E***t on 2026-03-15
A: This specific LQD-M85400-SR4C model is a commercial temperature (0°C to 70°C) transceiver, heavily optimized for climate-controlled indoor data centers and enterprise server rooms. If you need industrial wide-temp optics (-40°C to 85°C) for challenging outdoor base station cabinets, please contact our support team and we will direct you to the correct ruggedized SKU! By admin on 2026-03-15
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