Reed Semi Invalidates Key MPS Patent, Signals Further Legal Action

WARWICK, RI – January 26, 2026 – In a significant development reverberating through the competitive semiconductor industry, Reed Semiconductor Corp. has secured a decisive legal victory against rival Monolithic Power Systems, Inc. (MPS). The U.S. Patent and Trademark Office’s (USPTO) Patent Trial and Appeal Board (PTAB) issued a final written decision on January 22, invalidating all challenged claims of a key MPS patent related to power converter technology.

The ruling not only vindicates Reed’s long-held technical arguments but also signals a potential escalation in the intellectual property skirmishes between the two companies. In a bold follow-up statement, Reed announced its intention to pursue further legal action, alleging that MPS products infringe on its own patents, setting the stage for a new front in the industry’s ongoing patent wars.

A Decisive Ruling from the Patent Office

The case, designated IPR2024-01158, centered on U.S. Patent No. 9,041,377 B2, owned by Monolithic Power Systems. The patent, titled "Control apparatus and method for power converter," describes technology fundamental to the efficiency and performance of power management integrated circuits (ICs)—a core market for both companies. These components are ubiquitous, found in everything from consumer electronics and computing hardware to advanced automotive and industrial systems.

In its decision, the PTAB concluded that Reed Semiconductor had proven by a “preponderance of the evidence” that the claims of the ’377 patent were unpatentable. The board agreed with Reed’s assertion that the innovations described in the patent were not novel in light of existing technology, or “prior art,” that was publicly available before the patent was filed. As a result of the ruling, the patent’s claims are no longer enforceable, effectively neutralizing it as a competitive weapon for MPS.

This outcome represents a comprehensive validation of the legal and technical position maintained by Warwick-based Reed Semiconductor. “This outcome underscores Reed Semiconductor’s commitment to innovation grounded in sound engineering principles and respect for fair competition,” said Dr. Wenkai Wu, Reed Semiconductor’s CEO, in a statement. “We are pleased that the PTAB carefully evaluated the technical record and reached a decision consistent with the facts and the law.”

The High-Stakes Game of Patent Invalidation

The victory for Reed highlights the strategic importance of the PTAB, which was established by the America Invents Act of 2012 as a faster, more cost-effective forum than federal courts for challenging the validity of issued patents. For technology companies, an Inter Partes Review (IPR) proceeding has become a powerful tool to clear away what they deem to be weak patents that can stifle innovation and hinder competition.

Historically, the PTAB has been a favorable venue for petitioners. In recent years, a significant majority of IPR petitions that proceed to a final decision have resulted in at least some, if not all, challenged claims being invalidated. Reed’s success in having all challenged claims of the '377 patent struck down is a clear-cut win, removing a potential legal threat and opening up more design freedom in the lucrative power management space.

For companies in the capital-intensive semiconductor sector, where billions are spent on research and development, intellectual property is both a shield and a sword. Patents are used to protect groundbreaking innovations, but they are also wielded to block competitors and secure market share. The invalidation of a patent like the '377 patent can recalibrate the competitive landscape, allowing rivals to implement similar technologies without fear of an infringement lawsuit from the original patent holder.

Reed Semiconductor on the Offensive

Perhaps the most telling aspect of the announcement is not what Reed Semiconductor has won, but what it plans to do next. The company’s press release included a pointed declaration that it “intends to pursue additional actions demonstrating that MPS’s own products infringe the rights of Reed and others in the market.”

This statement signals a dramatic pivot from a defensive posture—challenging a competitor’s patent—to an offensive one. Reed is now publicly positioning itself as the aggrieved party, preparing to assert its own IP portfolio against MPS. This aggressive stance suggests that the PTAB victory was not merely about clearing a legal hurdle but was the opening salvo in a broader strategic campaign to challenge MPS’s market position.

The move lends weight to the leadership of Dr. Wenkai Wu, a respected industry veteran with a deep background in semiconductor engineering and executive management. By challenging the MPS patent while simultaneously preparing its own infringement claims, Reed is projecting confidence in the strength of its own innovations and its willingness to engage in complex, multi-front legal battles to protect them.

Ripple Effects for an Industry Leader

For Monolithic Power Systems, the ruling is a notable setback. As a leading global provider of high-performance analog and power solutions, MPS has built a formidable market presence and a reputation for strong financial performance, consistently reporting robust revenue growth and healthy profit margins. The company is no stranger to IP litigation, having been involved in various patent disputes over the years, a common feature of the highly competitive semiconductor landscape.

While the loss of a single patent is unlikely to cripple a company of MPS’s size and technical depth, it represents a vulnerability in its intellectual property armor. The invalidation of a patent covering core power converter technology could diminish its perceived IP strength and may embolden other competitors. Investors and market analysts will be watching closely to see if the invalidated technology was central to any key product lines or if it affects the company’s long-term competitive moat.

The industry will now await Reed’s next move. The specific patents Reed believes are being infringed by MPS have not yet been disclosed, but any forthcoming lawsuit will be scrutinized for its potential to disrupt product lines and alter the balance of power. This ruling by the PTAB, while conclusive on its own, appears to be just one chapter in a much larger and more complex story of innovation, competition, and legal strategy unfolding between two major industry players.