Reed Semiconductor Corp. v. Monolithic Power Systems, Inc.

Reed Semiconductor Corp. has initiated a patent infringement lawsuit against Monolithic Power Systems, Inc. in the U.S. District Court for the Western District of Texas. Reed Semiconductor, founded in 2019 and headquartered in Rhode Island, is an operating company that designs and manufactures advanced semiconductor solutions for power management, focusing on technologies for AI, high-performance computing, automotive, communications, and industrial applications. Monolithic Power Systems (MPS), a publicly traded American company established in 1997, is also an operating company specializing in analog and mixed-signal chips for power management across various markets, including cloud computing, telecom, automotive, and consumer electronics.

The lawsuit, filed on October 6, 2025, under case number 6:25-cv-00449, accuses Monolithic Power Systems of infringing claims 1, 2, 7, 8, and 9 of U.S. Patent No. 7,960,955. This patent, titled "Power Supply Device, Electronic Device Using the Same, and Semiconductor Device," generally describes a power supply architecture that employs a linear regulator to stabilize an input voltage, thereby isolating control circuitry from electrical noise and ensuring stable operation of power conversion in electronic devices. The accused products are identified as various MPS power management products that incorporate a linear regulator for input voltage stabilization, with the NB680 integrated circuit cited as a representative example. The case is proceeding in the Waco Division of the U.S. District Court for the Western District of Texas, presided over by Judge Alan D. Albright and Magistrate Judge Derek Neal Moore. Reed contends that venue is proper in the Western District of Texas due to MPS's established business presence there and its prior engagement in litigation within the district.

This litigation is notable as it appears to be part of a larger dispute between the two semiconductor companies. Reed's filing follows a series of lawsuits previously initiated by MPS against Reed in the U.S. District Court for the District of Delaware, which Reed characterizes as baseless. Beyond patent infringement, Reed's complaint also includes allegations that Monolithic Power Systems engaged in bad-faith interference with Reed's business relationships and contractual agreements. The case is set against the backdrop of intense competition in the fast-evolving semiconductor industry, particularly concerning power management solutions crucial for advanced applications like AI and data centers. Adding to its significance, Reed Semiconductor recently prevailed in a USPTO PTAB patent invalidation proceeding against Monolithic Power Systems regarding the '955 patent, reinforcing the patent's validity in the context of this ongoing dispute.

The patent infringement litigation, Reed Semiconductor Corp. v. Monolithic Power Systems, Inc., Case No. 6:25-cv-00449, is currently ongoing in the U.S. District Court for the Western District of Texas. The case involves U.S. Patent No. 7,960,955, and Reed Semiconductor Corp. has also alleged bad-faith interference with its business relationships.

Here's a chronological summary of key legal developments:

Filing & Initial Pleadings:

• October 6, 2025: Reed Semiconductor Corp. filed a patent infringement lawsuit against Monolithic Power Systems, Inc. (MPS) in the Western District of Texas. The complaint alleges infringement of claims 1, 2, 7, 8, and 9 of U.S. Patent No. 7,960,955, which covers power semiconductor devices incorporating a linear regulator to stabilize input voltage. Reed Semiconductor is represented by Morgan, Lewis & Bockius LLP. The complaint also includes allegations that MPS engaged in bad-faith interference with Reed's business relationships and contractual agreements.
• December 8, 2025: Plaintiff Reed Semiconductor served its preliminary infringement contentions.
• February 5, 2026: Defendant Monolithic Power Systems served its preliminary invalidity contentions.

Pre-Trial Motions of Substance:

• Prior to March 3, 2026: Monolithic Power Systems filed a motion to dismiss for improper venue under Rule 12(b)(3), lack of personal jurisdiction under Rule 12(b)(2), and lack of subject-matter jurisdiction under Rule 12(b)(1). Reed Semiconductor's response to this motion was due by March 3, 2026.
• April 17, 2026: A joint motion for a confidentiality/protective order was filed by Reed Semiconductor Corp.

Discovery Milestones:

• December 8, 2025: Plaintiff served preliminary infringement contentions.
• February 5, 2026: Defendant served preliminary invalidity contentions.
• February 17, 2026: The close of venue and jurisdictional discovery occurred.
• June 12, 2026: Fact discovery is scheduled to open, and initial disclosures per Rule 26(a) are due.
• July 23, 2026: The deadline to add parties is set.
• August 6, 2026: The deadline to serve final infringement and invalidity contentions is scheduled.
• January 7, 2027: Fact discovery is scheduled to close.
• January 14, 2027: Opening expert reports are due.
• February 11, 2027: Rebuttal expert reports are due.
• March 4, 2027: Expert discovery is scheduled to close.

Claim Construction (Markman):

• February 26, 2026: The parties exchanged claim terms for construction.
• March 12, 2026: The parties exchanged proposed claim constructions.
• March 26, 2026: The deadline for parties to meet and confer to narrow disputed terms and exchange revised lists of terms/constructions passed.
• April 2, 2026: Defendant filed its opening claim construction brief.
• April 23, 2026: Plaintiff filed its responsive claim construction brief.
• May 7, 2026: Defendant filed its reply claim construction brief.
• May 21, 2026: Plaintiff filed its sur-reply claim construction brief.
• June 11, 2026: A Markman hearing is tentatively scheduled for 9:00 a.m.

Parallel PTAB IPR Proceedings:

• December 1, 2025: Monolithic Power Systems, Inc. filed an Inter Partes Review (IPR2026-00165) petition challenging the validity of U.S. Patent No. 7,960,955 at the Patent Trial and Appeal Board (PTAB).
• April 14, 2026: The USPTO denied Monolithic Power Systems' validity challenge to U.S. Patent No. 7,960,955, upholding the patent. The IPR status for IPR2026-00165 is "Not Instituted - Procedural".
• January 22, 2026: In a separate but related proceeding (IPR2024-01158), Reed Semiconductor Corp. successfully challenged U.S. Patent No. 9,041,377 B2, owned by Monolithic Power Systems, Inc., at the PTAB. The PTAB issued a Final Written Decision finding all challenged claims of the '377 patent unpatentable, thus precluding their enforcement.

Current Posture:
The case is active and proceeding through the claim construction and discovery phases, with key dates scheduled into early 2027. There has been no settlement, dismissal, or trial verdict to date.

Reed Semiconductor Corp. is represented by attorneys from Morgan, Lewis & Bockius LLP. The following counsel have appeared for the plaintiff:

• Rick Rambo

  • Role: Counsel of record.
  • Firm and Office Location: Morgan, Lewis & Bockius LLP, Houston, TX.
  • Relevant Experience: Rick Rambo is listed as counsel of record for the plaintiff and has been served with documents in the case. His firm, Morgan Lewis, represents Reed Semiconductor Corp. in this patent infringement matter, which includes allegations of bad-faith interference with business relationships.

• Andrew Gray IV

  • Role: Counsel of record.
  • Firm and Office Location: Morgan, Lewis & Bockius LLP, Palo Alto, CA.
  • Relevant Experience: Andrew Gray IV is listed as counsel of record and has been served with documents related to the case.

• Jason White

  • Role: Counsel of record.
  • Firm and Office Location: Morgan, Lewis & Bockius LLP.
  • Relevant Experience: Jason White is listed as counsel of record for the plaintiff.

Monolithic Power Systems, Inc. is represented by attorneys from Foley & Lardner LLP and Fish & Richardson P.C. in this case.

Here is the identified counsel:

• Michael J. McKeon

  • Role: Lead Counsel.
  • Firm and Office Location: Fish & Richardson P.C., Washington, D.C..
  • Relevant Experience: Michael McKeon is a nationally recognized intellectual property and trial attorney with over 25 years of experience representing well-known companies in complex disputes. He has extensive experience in electrical technologies, including telecommunications, semiconductors, and consumer electronics. McKeon has led trial teams in federal district courts, the U.S. International Trade Commission (ITC), and has appeared before the Court of Appeals for the Federal Circuit. He previously worked as a Patent Examiner at the U.S. Patent and Trademark Office.

• Bryan Koh

  • Role: Counsel of record.
  • Firm and Office Location: Fish & Richardson P.C. (Specific office not found in provided search results, but Fish & Richardson has offices in Texas, including Dallas and Houston, which might serve as local counsel).
  • Relevant Experience: The provided search results do not contain specific information about Bryan Koh's individual patent litigation experience or notable past cases.

• John P. Schnurer

  • Role: Counsel of record.
  • Firm and Office Location: Foley & Lardner LLP, San Diego, CA.
  • Relevant Experience: John P. Schnurer is listed as counsel for Monolithic Power Systems, Inc., on a filing for proposed claim terms for construction.

• Kevin Patariu

  • Role: Counsel of record.
  • Firm and Office Location: Foley & Lardner LLP, San Diego, CA.
  • Relevant Experience: Kevin Patariu is listed as counsel for Monolithic Power Systems, Inc., on a filing for proposed claim terms for construction.

• Miguel J. Bombach

  • Role: Counsel of record.
  • Firm and Office Location: Foley & Lardner LLP, San Diego, CA.
  • Relevant Experience: Miguel J. Bombach is listed as counsel for Monolithic Power Systems, Inc., on a filing for proposed claim terms for construction.

While Monolithic Power Systems, Inc. also has a lawsuit history with Councill, Gunnemann & Chally, LLC, the provided docket entries and search results for this specific case, Reed Semiconductor Corp. v. Monolithic Power Systems, Inc. (6:25-cv-00449), specifically name Foley & Lardner LLP as counsel for the defendant for filings related to claim construction.