Broadcom QDD-SR4-400G Compatible 400G QSFP-DD SR4 Transceiver Module
Built for hosts recognizing QDD-SR4-400G, this HT-manufactured QSFP-DD module delivers 400G transmission at 850nm. Its rated reach is 30m on OM3 / 50m on OM4, with MPO-12/APC as the physical interface. The specifications and engineering guidance below support project teams keep OEM references, delivery records and port schedules aligned, while keeping HT manufacture separate from the OEM cross-reference.
OEM Part Number: QDD-SR4-400GHT Part Number: QDD-SR4-400G
Product Highlights
- Compatible alternative to Broadcom QDD-SR4-400G
- 400G connectivity at 400Gbps
- Optical wavelength: 850nm
- Specified reach: 30m on OM3 / 50m on OM4
- MPO-12/APC / MMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| HT Part Number | QDD-SR4-400G |
|---|---|
| Manufacturer | HT |
| Form Factor | QSFP-DD |
| Max. Data Rate | 400Gbps |
| Wavelength | 850nm |
| Max. Cable Distance | 30m@OM3/50m@OM4 |
| Connector | MPO-12/APC |
| Media | MMF |
| Transmitter Type | VCSEL 850nm |
| Receiver Type | PIN |
| TX Power | -4.6~4dBm |
| Minimum Receiver Power | -6.4dBm |
| Power Budget | 1.8dB |
| Receiver Overload | 4dBm |
| Max. Power Consumption | 8W |
| Extinction Ratio | 2.5dB |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation (Electrical) | 8x50G-PAM4 |
| Modulation (Optical) | 4x100G-PAM4 |
| DSP | TX and RX |
| Inbuilt FEC | Support |
| Core Size | 50/125µm |
| Packaging Technology | COB |
| MTBF | 1410258 Hours (@40°C, 90% CL) |
| Application | 400G Ethernet |
| Protocols | QSFP-DD MSA, CMIS Rev5.0, IEEE 802.3df-2024 |
Project Documentation and Traceability
Large deployments are easier to audit when the order code, optical standard and endpoint record agree. Keep the OEM reference in the compatibility document and the HT part number on the packing list. Labels and carton groups can be arranged by rack or port plan so installers need not identify modules by appearance. For this model, the principal parameters are data rate 400Gbps, wavelength 850nm, rated reach 30m on OM3 / 50m on OM4.
Broadcom Compatibility and Factory Testing
Compatibility testing for QDD-SR4-400G combines identification with a live link and available transmit, receive and alarm information. Connector condition is inspected separately. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.
Applications and Optical Link Design
This coherent interface is suited to data-center interconnect, metro transport and managed DWDM links where the host platform supports the stated modulation and FEC modes. Design the optical line around the actual launch power, receiver range, OSNR requirement and span loss; the stated reach is not a substitute for a link-budget calculation. Use matching coherent modules and the appropriate DWDM channel plan at both ends.
Before deployment, check the host port type, supported data rate and firmware requirements. The 400G interface configuration must match the remote equipment; sharing a QSFP-DD housing alone does not make two transceiver types interoperable.
Coherent deployment requires a line-system review, not merely a matching connector. Confirm the DWDM channel, launch-power range, receiver limits, OSNR and FEC mode at both ends. Span loss and amplifier operation must remain inside the supported envelope, and stated reach should be validated against the actual route.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -4.6~4dBm; the stated optical power budget is 1.8dB. A sound acceptance record includes link state, diagnostic temperature, supply voltage and transmit or receive levels where the host exposes them. Compare the readings with the stated ranges rather than treating any received light as proof of adequate margin. Persistent alarms or borderline values should trigger an end-face and complete-channel inspection. Diagnostic monitoring is listed as Supported. Before every insertion, keep dust caps in place until the patch lead is ready, avoid touching the optical end face and use an appropriate inspection and cleaning procedure. Do not look into an active optical interface.
Frequently Asked Questions
Is this an original Broadcom transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-SR4-400G, not an original Broadcom-branded module.
Which fiber and connector are required?
Use MPO-12/APC with MMF. The specified maximum reach is 30m on OM3 / 50m on OM4, subject to fiber quality and total link loss.
Can it be mixed with another wavelength or reach version?
Only when the two ends share the same optical standard, wavelength plan and supported data rate. Check the exact part numbers and link budget rather than relying only on the module form factor.
Ordering Information
When ordering, specify QDD-SR4-400G, QDD-SR4-400G, quantity and intended host platform. Project labels can repeat these details for receiving and asset records. Neutral labels, customer packaging and project-specific compatibility review are available on request.
Shipping and Lead Time
Standard configurations normally ship within one to three working days, with production lead times confirmed for larger quantities. International courier, air freight and sea freight are available; customer courier accounts and nominated forwarders are accepted.
Quality Assurance and Packaging
Before packing, the module receives interface inspection, identification and link checks. Protective packaging avoids pressure on the connector and latch. Customer references, rack groups and project packing lists can be added for volume orders.
