Credo Semiconductor Inc v. Volex PLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Credo Semiconductor Inc. (California) and Credo Technology Group Ltd. (Cayman Islands)
  • Defendant: Volex PLC (United Kingdom)
  • Plaintiff’s Counsel: Fish & Richardson P.C.
• Case Identification: 2:25-cv-00298, E.D. Tex., 03/18/2025
• Venue Allegations: Plaintiff alleges venue is proper in the district because the defendant is not a resident of the United States and may therefore be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant’s Active Electrical Cable (AEC) products infringe three patents related to high-speed data transmission technology.
• Technical Context: The technology at issue involves Active Electrical Cables (AECs), which incorporate signal-conditioning electronics to enable high-speed, high-volume data transmission over copper wiring, a critical component in modern data center infrastructure.
• Key Procedural History: The complaint alleges that Plaintiff sent a letter to Defendant on September 1, 2023, identifying its patent portfolio concerning AEC technology, including the patents-in-suit. This event is cited as the basis for pre-suit knowledge supporting the willfulness allegations.

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	Credo notice letter sent to Volex
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," Issued December 29, 2020

The Invention Explained

• Problem Addressed: The patent describes the increasing difficulty and cost of ensuring robust data transmission over copper cables at speeds beyond 50 Gbps and for distances greater than two meters, noting that conventional passive cables suffer from excessive signal attenuation and dispersion, while active optical cables are prohibitively expensive (ʼ233 Patent, col. 1:18-32).
• The Patented Solution: The invention is an active electrical cable that embeds data recovery and re-modulation (DRR) devices within its connectors. The core innovation is the use of preset, transmit-side "pre-equalization," where the signal is conditioned before it travels down the cable conductors using specific "transmit filter coefficient values" that are stored in nonvolatile memory within the cable itself (ʼ233 Patent, Abstract; col. 2:58-64). This pre-conditioning is intended to counteract the signal degradation expected from the cable, ensuring robust data transfer over longer distances (ʼ233 Patent, col. 8:5-21).
• Technical Importance: This approach claims to provide "affordable high-bandwidth data transport over distance spans up to at least seven meters," addressing a critical need in data centers for a cost-effective alternative to expensive optical solutions for medium-reach interconnects (ʼ233 Patent, col. 1:32-35).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶16).
• The essential elements of independent claim 1 include:
  • A first data recovery and re-modulation (DRR) device in a first connector plug.
  • A second DRR device in a second connector plug.
  • Electrical conductors connecting the first and second DRR devices.
  • The first and second DRR devices providing pre-equalization of the electrical transit signals that travel between them.
  • This pre-equalization uses "transmit filter coefficient values stored in nonvolatile memories."
• The complaint reserves the right to assert additional claims.

U.S. Patent No. 11,012,252 - "Active Ethernet Cable," Issued May 18, 2021

The Invention Explained

• Problem Addressed: The patent addresses the challenge of creating "affordable, mass-manufactured network hardware that assures consistently robust performance" as data rates increase beyond 50 Gbps, which strains the capabilities of conventional equalization techniques (ʼ252 Patent, col. 1:18-24).
• The Patented Solution: The invention is an active Ethernet cable with a transceiver in each connector. Each transceiver actively processes signals entering and exiting the cable. It performs clock and data recovery (CDR) on the electrical signal received from the host device to "extract and re-modulate the inbound data stream" before sending it through the cable conductors as a "transit signal" (ʼ252 Patent, Abstract). The patent explains that by performing CDR on both inbound and outbound data streams, the cable can ensure "consistently robust data transfer over extended cable lengths" without regard to the electronics of the connected host devices (ʼ252 Patent, col. 4:20-25).
• Technical Importance: This design allows the cable itself to guarantee signal integrity, making high-speed connections more reliable and interoperable across equipment from different manufacturers, thereby providing an affordable alternative to optical cables for longer-reach copper connections (ʼ252 Patent, col. 1:25-34).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶23).
• The essential elements of independent claim 1 include:
  • An active Ethernet cable with first and second connectors.
  • Each connector includes a respective transceiver that performs clock and data recovery on the "electrical input signal" from a host to "extract and re-modulate the inbound data stream."
  • The transceivers also perform clock and data recovery on the "electrical transit signal" traveling through the cable to create an "outbound data stream."
  • The transceivers employ "fixed, cable-independent, equalization parameters" for processing the electrical input signal and the outbound data stream.
• The complaint reserves the right to assert additional claims.

Multi-Patent Capsule

• Patent Identification: U.S. Patent No. 11,032,111, "SerDes Pre-Equalizer Having Adaptable Preset Coefficient Registers," Issued June 8, 2021 (Compl. ¶15).
• Technology Synopsis: This patent describes a method for efficiently adapting a transmitter's pre-equalizer in a high-speed SerDes (Serializer-Deserializer) link. The invention involves a transceiver that can select from multiple sets of preset pre-equalizer coefficients stored in different registers, where each register corresponds to a different channel model (e.g., a different cable length or type), and then update the selected coefficients during a link training phase (ʼ111 Patent, Abstract; col. 1:40-48).
• Asserted Claims: The complaint asserts at least independent claim 8 (Compl. ¶30).
• Accused Features: The complaint alleges that Volex's AECs infringe by incorporating and using SerDes technology that selects and adapts pre-equalizer coefficients in the claimed manner (Compl. ¶30).

III. The Accused Instrumentality

• Product Identification: The complaint identifies the accused products as Volex's "400G QSFP-DD AEC Cable, 400G QSFP112 AEC Cable, 800G QSFP-DD AEC Cable, 800G QSFP-DD to QSFP112 AEC Breakout Cable, 800G OSFP AEC Cable, and 800G OSFP to QSFP112 AEC Breakout Cable" (Compl. ¶16, 23, 30).
• Functionality and Market Context: The complaint describes the Accused Products as "active electrical cables" used for high-speed data transmission in the data infrastructure market (Compl. ¶1, 10). It alleges these products are marketed to meet the demands created by cloud computing, AI, and 5G wireless deployment (Compl. ¶12). The complaint cites a Volex press release announcing a demonstration of "industry-leading-performance-for-800g-active-copper-interconnects," suggesting the products are positioned at the high-performance end of the market (Compl. ¶18).

IV. Analysis of Infringement Allegations

The complaint references external claim chart exhibits (Exhibits 4, 5, and 6) to detail its infringement allegations; as these exhibits were not filed with the complaint, the following is a summary of the narrative infringement theory. No probative visual evidence provided in complaint.

’233 Patent Infringement Allegations

The complaint alleges that the Accused Products directly infringe at least claim 1 of the ’233 Patent (Compl. ¶16). The narrative theory is that Volex's AECs are cables containing internal data recovery and re-modulation (DRR) devices within their connectors. These devices allegedly perform "pre-equalization" on the electrical signals transmitted through the cable by using "transmit filter coefficient values stored in nonvolatile memories," thereby satisfying the core elements of the claim (Compl. ¶16; ’233 Patent, cl. 1).

’252 Patent Infringement Allegations

The complaint alleges that the Accused Products directly infringe at least claim 1 of the ’252 Patent (Compl. ¶23). The infringement theory is that the transceivers inside the Accused Products perform clock and data recovery on the electrical signals they receive from a host device before re-modulating and transmitting them through the cable. The theory further posits that this functionality, along with the processing of signals transiting the cable, is performed using "fixed, cable-independent, equalization parameters" as required by the claim (Compl. ¶23; ’252 Patent, cl. 1).

V. Key Claim Terms for Construction

• The Term: "transmit filter coefficient values stored in nonvolatile memories" (from ’233 Patent, claim 1)

• Context and Importance: This term is central to the ’233 Patent's claimed invention. The dispute will likely focus on whether the Accused Products actually store pre-equalization parameters in a "nonvolatile" medium and use them as "transmit filter coefficient values." Practitioners may focus on this term because proving the specific method of storage and use within a sealed, proprietary product will be a key evidentiary challenge.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification suggests the values are "determined and stored in the nonvolatile memories after assembly of the cable," which could support an interpretation covering any coefficients that are fixed post-manufacturing, regardless of the precise programming method (ʼ233 Patent, col. 2:40-43).
  • Evidence for a Narrower Interpretation: The detailed description of the manufacturing process refers to the automated tester "burning" the flash memory with the optimum values, which may support a narrower construction requiring a specific programming step where values are permanently written to a non-volatile medium like flash (ʼ233 Patent, col. 11:3-8).

• The Term: "fixed, cable-independent, equalization parameters" (from ’252 Patent, claim 1)

• Context and Importance: This term defines a key technical aspect of the ’252 Patent, distinguishing it from systems that use adaptive or cable-specific equalization. Infringement will depend on whether the parameters used in the Accused Products for the host-facing interface are truly "independent" of the specific cable's physical properties.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The term is used in claim 1 to describe the parameters for processing the host-side "electrical input signal" and the cable-side "outbound data stream," suggesting it could apply to any set of standardized, non-adaptive parameters used for those functions (ʼ252 Patent, cl. 1).
  • Evidence for a Narrower Interpretation: Dependent claim 2 explicitly introduces "cable-dependent equalization parameters" for other functions. A defendant may argue that this deliberate contrast implies that "cable-independent" in claim 1 must be strictly construed to mean parameters that are generic and unchanged across all cable lengths, types, and configurations. The specification reinforces this by stating these parameters are used for the host-facing components, while cable-dependent parameters are preferably used for the center-facing components (ʼ252 Patent, col. 3:56-col. 4:2).

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement for all three asserted patents. Inducement is based on allegations that Volex provides instructional materials, offers customer support, and demonstrates the Accused Products at trade shows, with the specific intent to encourage its customers and distributors to use the products in an infringing manner (Compl. ¶18, 25, 32). Contributory infringement is based on allegations that components of the Accused Products, such as their internal "clock and data recovery processors," are especially made for infringement and are not staple articles of commerce with substantial non-infringing uses (Compl. ¶19, 26, 33).
• Willful Infringement: The complaint alleges that Volex’s infringement is willful. The basis for this allegation is a claim of pre-suit knowledge stemming from a letter Credo sent to Volex on September 1, 2023, which allegedly identified the Asserted Patents. The complaint alleges that Volex continued its infringing activities unabated after receiving this notice (Compl. ¶21, 28, 35).

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

• A central issue will be one of evidentiary proof: can Credo, through discovery into the design and operation of Volex's proprietary chipsets, produce evidence showing that the Accused Products perform the specific functions of "pre-equalization" and "clock and data recovery" using the particular parameter types ("transmit filter coefficient values stored in nonvolatile memories" and "fixed, cable-independent, equalization parameters") required by the asserted claims?
• The case will also likely turn on a question of claim scope: how will the court construe the key technical limitations in the independent claims? The resolution of whether the terms require a specific method of programming nonvolatile memory ('233 Patent) or a strict degree of independence from cable characteristics ('252 Patent) will likely be determinative of infringement.
• A third key question will be one of technical causality: assuming Credo proves the Accused Products perform the claimed functions, does the evidence from Volex's marketing materials, user manuals, and customer support activities demonstrate the specific intent required to prove induced infringement, or can Volex argue it was merely instructing on the lawful use of a purchased product?