Broadcom Limited AFCT-91DRDHZ

Overview

AFCT-91DRDHZ from Broadcom is a QSFP-DD pluggable, single-mode fiber-optic transceiver for 400GbE DR4 applications, supporting 500 m reach over SMF. It implements 8×50-Gb/s PAM4 electrical input (400GAUI-8), 4×100-Gb/s optical output at 1310 nm, and complies with IEEE 802.3 Clause 124. It operates at 0°C to 70°C case temperature and integrates cooled EML lasers and PIN photodiodes for high-reliability data center interconnects.

For engineers reviewing the AFCT-91DRDHZ datasheet, pinout, applications, or equivalent options, this page delivers verified specifications, QSFP-DD mechanical and electrical interface details, digital diagnostic monitoring (DDM) register mapping, optical compliance context (400GBASE-DR4), and real-world selection guidance against comparable 400G DR4 modules.

Technical Context

The AFCT-91DRDHZ implements a full-duplex 400G DR4 architecture: eight 26.5625 GBd PAM4 electrical lanes (host-facing, 400GAUI-8 compliant with host KP FEC) are multiplexed into four 53.125 GBd PAM4 optical lanes using quad EML lasers and demultiplexed by quad PIN/TIA receivers. All high-speed I/O is internally AC-coupled and terminated to 100 Ω differential.

It features a two-wire serial (TWS) interface compliant with CMIS 4.0 for digital diagnostics-including real-time monitoring of module temperature (±3°C accuracy), supply voltage (±3%), TX bias current (±10%), RX input power (±3 dB), and TX output power (±3 dB)-with maskable interrupts (INTL) for LOS and Tx_FAULT reporting.

Key Specifications

Pinout & Package

AFCT-91DRDHZ uses the standard QSFP-DD mechanical form factor defined in the QSFP-DD MSA specification, with a 76-contact edge connector and integrated pull-tab for high-density insertion/extraction. The module incorporates internal AC coupling capacitors (0.1 µF) and requires no external termination on the host board.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 400G DR4 optical transceiver applications.

Compared with AFCT-91DRDHZ, AFCT-91DRPHZ extends reach to 2 km at the expense of DR4 compliance, while FTLC4421x3NL offers functional equivalence with relaxed DDM accuracy and reduced telemetry depth-making AFCT-91DRDHZ optimal for strict IEEE-conformance and predictive maintenance use cases.

Availability

AFCT-91DRDHZ is available at Aetrix Electronics and suitable for data center spine-leaf interconnects, hyperscale server aggregation, AI/ML cluster networking, and cloud provider optical backplanes requiring stable component supply, full CMIS 4.0 support, and IEEE 802.3 Clause 124 validation.

Supply support for AFCT-91DRDHZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Broadcom Inc. is a global semiconductor leader specializing in infrastructure software and silicon solutions for networking, storage, and broadband communications.

The AFCT-91DRDHZ belongs to Broadcom's QSFP-DD 400G transceiver product line, engineered specifically for high-density, energy-efficient 400GbE data center interconnects demanding IEEE compliance, Class 1 laser safety, and real-time digital diagnostics.

FAQ

What is the maximum supported link distance for AFCT-91DRDHZ?

The AFCT-91DRDHZ supports up to 500 meters over 9-µm single-mode fiber (SMF), as defined by IEEE 802.3 Clause 124 for 400GBASE-DR4. This distance assumes ≤1 dB fiber attenuation and ≤3 dB total connection/splice loss, with individual connector loss capped at 0.5 dB. The AFCT-91DRDHZ is not rated for 2 km operation-that capability belongs to the AFCT-91DRPHZ variant.

Does AFCT-91DRDHZ include forward error correction (FEC)?

The AFCT-91DRDHZ does not implement onboard FEC. It is designed exclusively for operation with host-generated KP FEC as specified in IEEE 400GAUI-8 (Annex 120E). The module expects precoded FEC signals from the host ASIC and provides no internal decoding or correction-ensuring deterministic latency and full compliance with the 400GBASE-DR4 standard.

What digital diagnostic monitoring (DDM) parameters does AFCT-91DRDHZ report?

The AFCT-91DRDHZ reports five calibrated DDM parameters via its CMIS 4.0 TWS interface: module case temperature (±3°C), +3.3 V supply voltage (±3%), per-channel transmitter laser bias current (±10%), per-channel receiver input optical power (±3 dB), and per-channel transmitter output optical power (±3 dB). All values are accessible through standardized memory pages (e.g., lower page 00h for temp/voltage, upper page 11h for optical metrics).

Is AFCT-91DRDHZ compatible with standard QSFP-DD cages and host boards?

Yes, AFCT-91DRDHZ fully complies with the QSFP-DD MSA mechanical and electrical specifications, including the 76-pin edge connector layout, thermal envelope, and pull-tab interface. It requires no host-board modifications-AC coupling capacitors and 100 Ω differential terminations are integrated internally, and all control signals (ModSelL, ResetL, SCL/SDA, IntL) adhere to LVTTL 3.3 V logic levels.

What laser safety classification applies to AFCT-91DRDHZ?

The AFCT-91DRDHZ is certified as a Class 1 laser product per EN 60825-1:2014 and 21 CFR 1040.10, with CDRH accession number 2110590-000. This classification confirms it is safe during normal operation and service, with no accessible laser radiation exceeding Class 1 limits-even under single-fault conditions-due to integrated safety interlocks and automatic transmitter disable on fault detection.