Credo Semiconductor Inc v. Amphenol Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Credo Semiconductor Inc. (California) and Credo Technology Group Ltd. (Cayman Islands)
  • Defendant: Amphenol Corporation (Delaware)
  • Plaintiff’s Counsel: Fish & Richardson P.C.; Gillam & Smith, LLP
• Case Identification: 2:25-cv-00296, E.D. Tex., 03/18/2025
• Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas because Defendant Amphenol has offered to sell the accused products to customers in the district and maintains a regular and established place of business, specifically a manufacturing facility, within the district.
• Core Dispute: Plaintiff alleges that Defendant’s high-speed Active Electrical Cables (AECs) infringe three patents related to signal conditioning and data processing technologies used to ensure reliable data transmission.
• Technical Context: The lawsuit concerns Active Electrical Cables (AECs), a critical component in modern data centers for connecting servers and switches, which are facing increasing technical challenges to transmit data at higher speeds over copper wiring.
• Key Procedural History: The complaint alleges that Plaintiff provided Defendant with notice of the asserted patents on September 1, 2023, via a letter that identified its patent portfolio concerning AEC technology. Subsequent negotiations between the parties were reportedly unsuccessful.

Case Timeline

Date	Event
2018-08-28	Earliest Priority Date for ’111 Patent
2019-03-01	Earliest Priority Date for ’252 Patent
2019-11-27	Earliest Priority Date for ’233 Patent
2020-12-29	’233 Patent Issued
2021-05-18	’252 Patent Issued
2021-06-08	’111 Patent Issued
2023-09-01	Plaintiff allegedly put Defendant on notice of the Asserted Patents
2025-03-18	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 10,877,233 - "Active Ethernet Cable with Preset Pre-Equalization"

The Invention Explained

• Problem Addressed: As data transmission speeds increase over copper cables, signals suffer from greater attenuation and dispersion, which necessitates complex and power-hungry equalization at the receiver end ('233 Patent, col. 1:15-24, 1:39-42).
• The Patented Solution: The patent describes an "active" cable with a data recovery and re-modulation (DRR) device at each end. Instead of relying solely on the receiver to clean up a degraded signal, these DRR devices apply "pre-equalization" to the signal before it is sent across the cable. This is accomplished using transmit filter coefficient values that are pre-determined and stored in nonvolatile memory within the cable's connector, effectively pre-compensating for the distortion the signal is expected to encounter ('233 Patent, Abstract; col. 2:11-14).
• Technical Importance: This transmit-side equalization approach aims to reduce the burden on the receiver, which can lower power consumption and cost, a significant concern in large-scale data centers ('233 Patent, col. 10:43-53).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶17).
• Essential elements of claim 1 include:
  • A first and second data recovery and re-modulation (DRR) device, each in a connector plug at opposite ends of a cable.
  • Electrical conductors connecting the two DRR devices.
  • The DRR devices converting between multi-lane data streams from a host and "electrical transit signals" conveyed over the conductors.
  • Crucially, the first and second DRR devices provide pre-equalization of the electrical transit signals using transmit filter coefficient values stored in nonvolatile memories.
• The complaint does not explicitly reserve the right to assert dependent claims but makes allegations as to "at least" the identified claim (Compl. ¶17).

U.S. Patent No. 11,012,252 - "Active Ethernet Cable"

The Invention Explained

• Problem Addressed: The patent addresses the challenge of ensuring "consistently robust performance" for high-speed data transmission in mass-produced network hardware, where variables like cable length and manufacturing differences can degrade signals ('252 Patent, col. 1:19-23).
• The Patented Solution: The invention is an active cable where transceivers at each end perform Clock and Data Recovery (CDR) on signals traveling in both directions. A transceiver not only recovers and re-modulates the signal received from the other end of the cable (the "transit signal") to send to its host, but it also performs CDR on the "inbound data stream" received from its host before re-modulating it for transit across the cable's internal conductors. This ensures a clean, retimed signal is sent across the cable, regardless of the quality of the signal provided by the host device ('252 Patent, Abstract; col. 4:1-4).
• Technical Importance: By actively managing the signal integrity at both entry and exit points of the cable assembly, the invention aims to make high-speed connections more reliable and less dependent on the specific characteristics of the connected host equipment ('252 Patent, col. 4:10-25).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶24).
• Essential elements of claim 1 include:
  • An active Ethernet cable with electrical conductors between a first and second connector.
  • Each connector has a respective transceiver.
  • Each transceiver performs clock and data recovery on the electrical input signal (from the host) to extract and re-modulate the inbound data stream for transit across the conductors.
  • Each transceiver also performs clock and data recovery on the electrical transit signal (from the cable) to extract and re-modulate the transit data stream as an outbound signal to the host.
• The complaint does not explicitly reserve the right to assert dependent claims but makes allegations as to "at least" the identified claim (Compl. ¶24).

U.S. Patent No. 11,032,111 - "SerDes Pre-Equalizer Having Adaptable Preset Coefficient Registers"

Technology Synopsis

The patent describes a method for efficiently adapting a transmitter's pre-equalizer in a high-speed SerDes (Serializer/Deserializer) link. The invention proposes having multiple registers that store different sets of initial pre-equalizer coefficient values, each corresponding to a different channel model (e.g., different cable lengths or types). During startup, the system can test these preset configurations to quickly find the best starting point for fine-tuning, which is more efficient than a blind search ('111 Patent, Abstract).

Asserted Claims

The complaint asserts at least independent claim 8 (Compl. ¶31).

Accused Features

The complaint alleges that Amphenol's AECs, which utilize SerDes and Digital Signal Processor (DSP) technologies, infringe by making, using, or selling cables that practice the claimed invention (Compl. ¶11, ¶31).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are Amphenol’s active electrical cables, specifically identified as its "OSFP Cable Assembly, DSP Active, 32AWG, 112G / Lane" and "QSFP DD Cable Assembly, DSP Active, 32AWG, 112G / Lane" products (Compl. ¶17).

Functionality and Market Context

These products are high-speed wired connectivity solutions used in the data infrastructure market, such as in data centers, to handle the high volumes of data generated by cloud workloads, AI, and 5G deployment (Compl. ¶11, ¶13). The complaint alleges these cables incorporate DSP and SerDes technologies to enable data transmission at high speeds (e.g., 112G/Lane) (Compl. ¶11, ¶17). The complaint references an Amphenol LinkedIn post regarding demonstrations of its AEC products at a trade show, indicating their active promotion to the market (Compl. ¶19). The referenced post notes demonstrations of the Accused Products at the DesignCon 2023 trade show (Compl. ¶19).

IV. Analysis of Infringement Allegations

The complaint states that claim charts for each asserted patent are attached as Exhibits 4, 5, and 6; however, these exhibits were not provided with the complaint document. The following is a summary of the infringement theories based on the text of the complaint.

’233 Patent Infringement Allegations

The complaint alleges that Amphenol’s Accused Products infringe at least claim 1 of the ’233 patent because they are active electrical cables that perform pre-equalization on the signals they transmit internally (Compl. ¶1, ¶17). The core of this infringement theory is that the DSPs within Amphenol's cable connectors apply pre-set, transmit-side filtering to signals before they travel the length of the cable, which corresponds to the claimed "pre-equalization of the electrical transit signals using transmit filter coefficient values stored in nonvolatile memories" (’233 Patent, cl. 1).

’252 Patent Infringement Allegations

The complaint alleges that the same Accused Products infringe at least claim 1 of the ’252 patent (Compl. ¶24). The infringement theory centers on the dual clock-and-data-recovery (CDR) functionality of the transceivers within the cable connectors. The allegation is that Amphenol's products perform CDR not only on the signal received from the far end of the cable but also on the signal received from the local host equipment before transmitting it across the cable. This functionality is alleged to map onto the claim language requiring a transceiver that "performs clock and data recovery on the electrical input signal to extract and re-modulate the inbound data stream" for transit (’252 Patent, cl. 1).

V. Key Claim Terms for Construction

Term: "pre-equalization" (from '233 Patent, claim 1)

Context and Importance

The entire infringement case for the ’233 patent hinges on whether the accused AECs perform "pre-equalization" as claimed. The scope of this term will determine if Amphenol's signal conditioning methods fall within the patent. Practitioners may focus on this term because the distinction between generic transmit-side signal shaping and the specific "pre-equalization" taught in the patent is a likely point of dispute.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The specification describes the concept generally as "transmit-side equalization" and a "pre-equalization filter" that converts a digital data stream into an analog signal with "spectral shaping to combat channel degradation" ('233 Patent, col. 10:43-51), which could support a reading on various forms of transmit-side filtering.
• Evidence for a Narrower Interpretation: The patent also describes specific implementations, such as a "long-tap" filter with "up to 30 or more taps" ('233 Patent, col. 10:53-57) and determination of coefficient values during manufacturer testing ('233 Patent, col. 2:38-41, col. 10:11-14). These specific embodiments could be used to argue for a narrower definition tied to these characteristics.

Term: "performs clock and data recovery on the electrical input signal to extract and re-modulate the inbound data stream" (from ’252 Patent, claim 1)

Context and Importance

This multi-step process defines the core functionality for handling signals entering the cable from the host. The infringement analysis for the ’252 Patent will depend on whether Amphenol's products perform this full sequence, as opposed to a simpler re-driving or amplification function.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The abstract describes the function as a transceiver that "performs clock and data recovery on the electrical input signal to extract and re-modulate the inbound data stream for transit," suggesting a complete retiming and regeneration of the signal ('252 Patent, Abstract).
• Evidence for a Narrower Interpretation: The detailed description is sparse on alternative embodiments for this specific function, repeatedly describing it as "CDR and re-modulation" ('252 Patent, col. 3:65-4:4). A defendant might argue that this term requires a full CDR circuit as conventionally understood, and that a simpler signal repeater would not meet this limitation.

VI. Other Allegations

Indirect Infringement

The complaint alleges both induced and contributory infringement for all three patents. Inducement allegations are based on Amphenol allegedly providing materials, instructions, data sheets, and customer support, as well as demonstrating the Accused Products at trade shows, with the specific intent that customers and distributors use the products in an infringing manner (Compl. ¶19, ¶26, ¶33). The complaint references a LinkedIn post about product demonstrations at a trade show as an example of such inducement (Compl. ¶19). Contributory infringement is alleged on the basis that components of the Accused Products, like the DSPs, are especially made for use in the infringing cables, are a material part of the invention, and are not staple articles of commerce with substantial non-infringing uses (Compl. ¶20, ¶27, ¶34).

Willful Infringement

Willfulness is alleged for all three patents based on pre-suit knowledge. The complaint asserts that Credo put Amphenol on notice of the patents-in-suit in a letter dated September 1, 2023. It further alleges that subsequent negotiations were unsuccessful and that Amphenol continued its allegedly infringing conduct despite this knowledge, creating an objectively high risk of infringement (Compl. ¶18, ¶22, ¶25, ¶29, ¶32, ¶36).

VII. Analyst’s Conclusion: Key Questions for the Case

This case appears to center on the specific internal workings of Amphenol's high-speed cables. The outcome will likely be determined by the answers to two primary questions:

1. A central evidentiary question will be one of technical operation: Does discovery reveal that Amphenol’s AECs internally perform the precise signal processing steps recited in the claims? Specifically, do they use "preset" coefficients from nonvolatile memory for "pre-equalization" (the '233 patent), and do they perform a full "extract and re-modulate" CDR process on signals received from the host (the '252 patent), or do they employ functionally distinct, non-infringing methods?

2. A critical legal question will be one of claim construction: How broadly will the court define the key technical terms, such as "pre-equalization" and the multi-part CDR process? The viability of Credo's infringement case rests on a construction of these terms that is broad enough to read on the functionality of Amphenol’s accused products.