AFCT-91FRDDZ Avago Compatible 400GBASE-FR4 QSFP-DD Transceiver

EdgeOptic's AFCT-91FRDDZ compatible is an Avago/Broadcom-coded 400GBASE-FR4 QSFP-DD transceiver that drops into a QSFP-DD host port programmed for the original Avago module. Same 2 km duplex single-mode reach, same LC/UPC connector, and same optical and electrical envelope as the Avago part, with EEPROM coded so the host accepts the module on insertion. Now part of Broadcom Inc. following Avago's 2016 acquisition of Broadcom Corporation, the AFCT-91FRDDZ retained the AFCT- prefix that Avago uses across its transceiver module family.

Four CWDM wavelengths at 1271, 1291, 1311, and 1331 nm multiplex onto a single duplex pair. PAM4 modulation at 53.125 GBaud per lane delivers 400 Gb/s aggregate throughput. EML transmitters drive each wavelength channel; PIN photodiode receivers handle the inbound side. TX power is -3.3 to +3.5 dBm per lane, RX sensitivity is -7.3 dBm. The 4 dB optical link budget covers a 2 km OS2 span with margin for patch panels and splices in normal data center cabling environments. Host-side electrical interface is 400GAUI-8 with eight 53.125 Gbps PAM4 lanes.

The AFCT-91FRDDZ is 400GBASE-FR4, which uses an LC duplex connector over single-mode fiber. Some third-party listings misclassify it with an MTP/MPO connector; that is incorrect for the FR4 type. FR4 multiplexes four CWDM wavelengths onto a single duplex fiber pair through the LC connector. The AFCT-91 family does include MPO-connector variants, but those are different products: the AFCT-91DRDHZ is 400GBASE-DR4 with parallel 1310 nm PSM4 lanes on an MPO-12 connector at 500 m, and the AFCT-91DRPHZ is another MPO-connector sibling in the AFCT-91 family. Different module, different connector, different fiber infrastructure. Verify the exact suffix on the chassis transceiver table or installed module label before ordering.

The original AFCT-91FRDDZ was an OEM transceiver component shipped into 400G switching and routing platforms. EdgeOptic codes the compatible for Cisco, Arista, Juniper, and other targets so the same FR4 module can replace a failed Avago part across mixed-vendor sites. On Cisco platforms, EdgeOptic programs Cisco-recognized EEPROM so the module is accepted natively without the service unsupported-transceiver workaround. Specify the target chassis vendor on the order and the module ships pre-coded for that platform; verify host compatibility against the platform vendor's transceiver matrix for the specific software release.

Conforms to IEEE 802.3cu, 100G Lambda MSA 400G-FR4, QSFP-DD MSA, and CMIS 4.0. CMIS exposes per-lane TX and RX optical power, module case temperature, supply voltage, and laser bias current over standard I2C, so DOM integrates with existing chassis monitoring through standard NOS diagnostic commands. KP4 RS-FEC (RS(544,514)) is required from the host ASIC to meet the PAM4 BER target. Class 1 laser safe per IEC 60825-1, CE and RoHS certified, commercial temperature 0 to 70 °C, under 10 W power consumption.

FR4 fits 400G data center interconnect, leaf-spine uplinks, and aggregation above a 100G leaf layer. Duplex LC patching keeps structured cabling simple where the existing single-mode plant already uses LC, the alternative to MPO-12 parallel optics on DR4. 2 km covers most intra-campus runs.

Backed by 15+ years of EdgeOptic compatibility engineering across vendor optical platforms. Made to order with a 2-week lead time and lifetime warranty included. For volume pricing or platform-specific EEPROM coding requests, contact our sales team.