DCT

1:25-cv-00863

Micron Technology Inc v. Netlist Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00863, D. Del., 07/29/2025
  • Venue Allegations: Plaintiff Micron alleges venue is proper in the District of Delaware because Defendant Netlist is a Delaware corporation and is subject to personal jurisdiction in the district.
  • Core Dispute: Plaintiff seeks a declaratory judgment that its DDR4 and DDR5 DIMM memory module products do not infringe Defendant’s patent related to memory module circuits for improving signal integrity.
  • Technical Context: The technology at issue addresses methods for reducing signal noise and managing electrical load in high-speed computer memory modules, a critical factor for performance in servers, personal computers, and other data-intensive systems.
  • Key Procedural History: The complaint alleges a history of litigation between the parties, including lawsuits filed by Netlist in the Western and Eastern Districts of Texas. This declaratory judgment action follows a demand letter from Netlist and a separate infringement suit filed by Netlist in the Eastern District of Texas asserting the same patent-in-suit against Micron.

Case Timeline

Date Event
2008-04-14 ’731 Patent Priority Date
2018-07-17 ’731 Patent Issue Date
2021-04-28 Netlist sends demand letter to Micron alleging infringement by the ’731 Patent
2021-05-19 Netlist sends follow-up letter regarding licenses for Micron's RDIMM, LRDIMM, and NVDIMM products
2023-07-01 Netlist representatives begin conducting inspections of Micron's electronic design files (approximate start)
2023-10-31 Netlist inspections of Micron's electronic design files conclude (approximate end)
2025-07-29 Complaint for Declaratory Judgment Filed

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

U.S. Patent No. 10,025,731 - "MEMORY MODULE AND CIRCUIT PROVIDING LOAD ISOLATION AND NOISE REDUCTION"

The Invention Explained

  • Problem Addressed: As computer systems increase in speed and memory density, the electrical signals traveling between a memory controller and memory chips can degrade. This can be caused by signal reflections from impedance mismatches and "heavy fan-outs" where one signal path must drive many components, leading to reduced performance and higher power consumption (Compl. Ex. A, ’731 Patent, col. 1:51-2:14).
  • The Patented Solution: The invention describes a memory module that incorporates a specialized circuit between the module's main connector and its memory chips. This circuit is designed to both isolate unused memory banks ("ranks") and actively correct signal noise. It achieves this with a "switching sub-circuit" that selectively connects the memory controller to the desired memory rank, and a "correction circuit" that reduces noise, for example, through impedance matching to prevent signal reflections (’731 Patent, Abstract; col. 5:21-40).
  • Technical Importance: This approach aims to enhance memory subsystem performance by actively managing signal integrity on the memory module itself, potentially allowing for higher speeds and densities without the performance degradation typically associated with such increases (’731 Patent, col. 4:30-56).

Key Claims at a Glance

  • The complaint asserts non-infringement of independent claim 1 (Compl. ¶28).
  • Essential elements of independent claim 1 include:
    • A memory module with a printed circuit board (PCB) and connector.
    • A plurality of memory devices on the PCB arranged in multiple "ranks."
    • "at least one circuit" coupled between the connector and the memory devices.
    • This circuit includes a "set of correction circuits" for signals, with each correction circuit including "at least one programmable impedance matching circuit."
    • "control circuitry" that receives signals from the system memory controller.
    • This control circuitry is further configured to "dynamically control" the programmable impedance matching circuit based on which of the multiple memory ranks is selected for communication.
  • The complaint does not explicitly reserve the right to seek judgment on any dependent claims.

III. The Accused Instrumentality

Product Identification

  • Micron’s DDR4 and DDR5 Dual In-Line Memory Module (DIMM) products (Compl. ¶13).

Functionality and Market Context

  • The complaint describes the accused products as standard-generation memory modules (DDR4 and DDR5) but does not provide specific technical details on their internal architecture or operation (Compl. ¶29).
  • The complaint alleges that Micron is a "world leader in innovative computer-memory and data-storage solutions" (Compl. ¶2). No further details on the market positioning of the specific accused products are provided.

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

This is a declaratory judgment action for non-infringement. The table below summarizes Micron's specific contentions that its products are missing certain required claim elements. The complaint makes these allegations at a high level without providing a detailed technical comparison.

’731 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Non-Infringing Functionality Complaint Citation Patent Citation
...at least one circuit ... comprising a set of correction circuits... the each correction circuit of the set of correction circuits including at least one programmable impedance matching circuit; Micron alleges its DDR4 and DDR5 DIMM products do not contain this claimed element. ¶30 col. 17:11-21
...control circuitry... further configured to dynamically control the at least one programmable impedance matching circuit... based on which of the multiple ranks is selected... Micron alleges its DDR4 and DDR5 DIMM products do not contain control circuitry that performs this claimed function. ¶31 col. 17:22-34
  • Identified Points of Contention:
    • Scope Questions: The dispute may center on the definition of "programmable impedance matching circuit." A key question for the court could be whether any impedance control features in Micron's products, if they exist, fall within the scope of this term as it is used and defined in the patent.
    • Technical Questions: A primary factual dispute will likely be whether Micron's products contain circuitry that "dynamically control[s]" impedance "based on which of the multiple ranks is selected." The complaint’s denial suggests the possibility that any impedance management in its products is either static, not programmable in the claimed manner, or not responsive to rank selection signals.

V. Key Claim Terms for Construction

The Term: "programmable impedance matching circuit"

  • Context and Importance: This term is central to Micron’s non-infringement contention. The existence and nature of such a circuit in the accused products will be a core issue. Practitioners may focus on this term because its definition will determine whether the circuitry in Micron's products meets this limitation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent specification suggests this element could be a "network of resistors which can be configured to provide programmable impedance matching" (’731 Patent, col. 10:59-62), which might be argued to encompass a variety of configurable circuits.
    • Evidence for a Narrower Interpretation: The specification describes the circuit as being "controllable by a control signal" and that its impedance values may be "dynamically controllable" (’731 Patent, col. 10:51-54, col. 11:11-12). This could support a narrower construction requiring a circuit that is actively and dynamically adjusted during operation, rather than one that is merely configurable.

The Term: "dynamically control"

  • Context and Importance: This term, which modifies the function of the "control circuitry," is the subject of Micron's second specific non-infringement argument. The dispute will likely involve whether the control scheme in Micron's products, if any, performs this specific action.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term itself might be argued to mean any control that is not fixed or static, occurring during the device's operation.
    • Evidence for a Narrower Interpretation: The full claim phrase requires the dynamic control to be "based on which of the multiple ranks is selected to communicate data" (’731 Patent, col. 17:29-32). This language suggests a direct, responsive link between the rank selection signal and the impedance control, potentially excluding control schemes that are set at boot-up or are not directly tied to real-time rank access.

VI. Other Allegations

  • Indirect Infringement: Micron seeks a declaration that it does not indirectly infringe any claim of the ’731 patent, but the complaint does not allege specific facts regarding inducement or contributory infringement beyond a general denial of liability (Compl. ¶34; Prayer for Relief ¶a).
  • Willful Infringement: This allegation is not applicable, as the complaint is a declaratory judgment action for non-infringement filed by the accused infringer.

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

  • A core issue will be one of definitional scope: How will the court construe the term "programmable impedance matching circuit"? The outcome may depend on whether the term requires a specific type of actively adjustable circuit, as opposed to any form of configurable impedance control.
  • A second key issue will be both technical and definitional: What level of responsiveness and control is required by the limitation that the control circuitry must "dynamically control" the impedance "based on which of the multiple ranks is selected"? The case may turn on whether the accused products’ control architecture creates the specific, rank-responsive linkage required by the claim.
  • A central evidentiary question will be the factual determination of the precise architecture and method of operation of the signal integrity features within Micron's accused DDR4 and DDR5 DIMM products, as the complaint does not provide these technical details.