Delta Electronics Inc v. Vicor Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Delta Electronics, Inc. (Republic of China)
  • Defendant: Vicor Corporation (Delaware)
  • Plaintiff's Counsel: Haltom & Doan
• Case Identification: 7:26-cv-00288, W.D. Tex., 07/31/2026
• Venue Allegations: Venue is based on Defendant Vicor maintaining a regular and established place of business in the district, specifically an office in Cedar Park, Texas, which is also the location of a subsidiary alleged to be an alter ego of Vicor.
• Core Dispute: Plaintiff alleges that Defendant's DC/DC power converter products infringe a patent related to a circuit architecture that reduces power loss and improves efficiency.
• Technical Context: The lawsuit concerns DC/DC power converters, which are essential components for managing power delivery in high-performance electronics, such as data center servers, where energy efficiency is a critical design parameter.
• Key Procedural History: The complaint notes that the parties are direct competitors and have been engaged in extensive patent litigation against each other for several years across multiple forums, including U.S. district courts and the International Trade Commission (ITC). This history is cited to support allegations that Defendant had pre-suit knowledge of the patent-in-suit and its alleged infringement.

Case Timeline

Date	Event
2020-07-06	Priority Date for U.S. Patent No. 11,923,772
2022-01-06	U.S. patent application corresponding to the '772 Patent published
2023-07-01	Vicor initiated ITC and district court actions against Delta
2023-10-01	Delta filed a patent infringement suit against Vicor in W.D. Tex.
2023-11-01	Delta filed a patent infringement suit against Vicor in D. Del.
2024-03-05	U.S. Patent No. 11,923,772 issued
2026-01-12	Vicor initiated an ITC investigation against Delta
2026-07-31	Complaint filed in the present case

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

U.S. Patent No. 11,923,772 - "DC/DC Converter for Decreasing Power Loss Caused Parasitic Resistance and Increasing Equivalent Capacitance of High-Voltage Side Capacitor"

• Patent Identification: U.S. Patent No. 11,923,772 ("the '772 Patent"), titled "DC/DC Converter for Decreasing Power Loss Caused Parasitic Resistance and Increasing Equivalent Capacitance of High-Voltage Side Capacitor," issued on March 5, 2024 (Compl. ¶17; '772 Patent, (54)).

The Invention Explained

• Problem Addressed: The patent's background section describes issues in conventional DC/DC converters where AC current loops flow through both high-voltage and low-voltage side capacitors, creating an equivalent series resistance (ESR) that causes significant power loss Compl. ¶25 '772 Patent, col. 1:39-49 Additionally, the high DC voltage typically applied across the high-voltage capacitor can reduce its effective capacitance, limiting performance '772 Patent, col. 1:53-61
• The Patented Solution: The invention proposes a novel circuit topology for a non-isolated DC/DC converter where the high-voltage side capacitor (C1) is uniquely connected between the high-voltage positive input terminal (V1+) and the low-voltage positive output terminal (V2+) '772 Patent, col. 2:10-14 '772 Patent, FIG. 1 This reroutes AC current paths to prevent them from flowing through both the high- and low-voltage capacitors simultaneously, thereby shortening the current path and reducing power loss from parasitic resistance '772 Patent, col. 4:5-15 This configuration also lowers the DC voltage across the high-voltage capacitor, which increases its equivalent capacitance and improves filtering performance '772 Patent, col. 4:22-29
• Technical Importance: By improving efficiency and reducing power loss, this design addresses key challenges in power delivery for high-density computing environments like data centers Compl. ¶¶2, 23

Key Claims at a Glance

• The complaint asserts dependent claim 4 of the '772 Patent Compl. ¶37 Claim 4 depends from claim 3, which in turn depends from independent claim 1.
• The essential elements of the asserted claim combination include:
  • A DC/DC converter with a first end (high-voltage terminals) and a second end (low-voltage terminals) '772 Patent, claim 1
  • A "first capacitor" connected between the high-voltage positive terminal and the low-voltage positive terminal '772 Patent, claim 1
  • A "power conversion circuit" that includes a "first switch group" and a "second switch group" '772 Patent, claim 3
  • The power conversion circuit's "magnetic assembly" comprising a first inductor, a second inductor, and a transformer with specific winding and terminal connections to the switch groups '772 Patent, claim 4
• The complaint reserves the right to assert additional claims Compl. ¶40

III. The Accused Instrumentality

Product Identification

• The complaint identifies the "Vicor Accused Products" as a category of infringing devices, providing two exemplary products: the NBM™ Bus Converter (Model No. NBM2317S60D1580T0R) and the DCM™ DC-DC Converter (Model No. DCM3717S60D13K0TN1) Compl. ¶¶38-39

Functionality and Market Context

• The accused products are DC/DC converters designed, manufactured, and sold by Vicor for applications such as power supplies for servers Compl. ¶37 The complaint alleges these products are used in high-density, high-efficiency applications, including AI servers and data centers, placing them in direct competition with Delta's products Compl. ¶3 Compl. ¶33 To support allegations of Vicor's business presence in the venue, the complaint includes a screenshot from Vicor's website listing its Cedar Park, Texas office as an "additional location" Compl. ¶13 The complaint also provides a screenshot of a job posting for an engineering position at the same Texas office, allegedly to further demonstrate Vicor's established presence in the district Compl. ¶14

IV. Analysis of Infringement Allegations

The complaint references claim charts attached as Exhibits 2 and 4, which purport to show how the exemplary NBM™ and DCM™ accused products satisfy the limitations of claim 4 of the '772 Patent Compl. ¶¶38-39 As these exhibits were not included with the complaint, a table-based analysis is not possible.

The narrative infringement theory alleges that Vicor directly infringes by making, using, and selling the Accused Products, which are alleged to be DC/DC converters that practice every element of at least claim 4 Compl. ¶37 Compl. ¶52 The complaint states that the (un-provided) claim charts illustrate this element-by-element satisfaction for the exemplary products Compl. ¶¶38-39 Without these exhibits, the specific mapping of accused product features to the detailed limitations of claim 4-particularly the specific configuration of the internal switches, inductors, and transformer-remains a matter for discovery.

• Identified Points of Contention:
  • Technical Question: A central factual dispute will be whether the internal circuit architecture of Vicor's accused converters precisely matches the claimed configuration. This will require a detailed technical comparison of the accused products' schematics against the specific limitations of claim 4, including the unique connection of the "first capacitor" and the arrangement of the "magnetic assembly" components.
  • Evidentiary Question: What evidence will Delta produce to demonstrate that the physical embodiment of the Accused Products contains the specific multi-part "magnetic assembly" (first inductor, second inductor, transformer) and switch groups as defined in claim 4?

V. Key Claim Terms for Construction

• The Term: "a first capacitor, wherein a first terminal of the first capacitor is electrically connected with the high-voltage positive terminal, and a second terminal of the first capacitor is electrically connected with the low-voltage positive terminal" (from claim 1).

  • Context and Importance: This limitation describes the core architectural novelty of the patent, which re-routes the AC current loop to improve efficiency. Infringement hinges on whether the accused products utilize this specific, unconventional capacitor connection.
  • Intrinsic Evidence for a Broader Interpretation: The patent's summary and detailed description present this connection as a general principle of the invention, not tied to a single embodiment, which may support a broader application of the term '772 Patent, col. 2:10-14 '772 Patent, col. 4:1-5
  • Intrinsic Evidence for a Narrower Interpretation: A party could argue that the term must be understood in the context of the specific symmetric or asymmetric resonant topologies disclosed in the preferred embodiments and figures, potentially narrowing its scope against accused products that use a different underlying topology '772 Patent, FIG. 2A '772 Patent, FIG. 3

• The Term: "the at least one magnetic assembly comprises a first inductor, a second inductor and a transformer" (from claim 4).

  • Context and Importance: Claim 4 recites a specific combination of three distinct magnetic components. The dispute will likely focus on whether the accused devices contain this exact combination or a functionally similar but structurally different magnetic arrangement.
  • Intrinsic Evidence for a Broader Interpretation: The patent discloses that the inductors could be discrete components or derived from the transformer's leakage inductance, suggesting some flexibility in the physical implementation '772 Patent, col. 5:35-42 '772 Patent, claims 5-6
  • Intrinsic Evidence for a Narrower Interpretation: A defendant might argue that its device uses a single, integrated magnetic component that does not constitute the explicitly recited combination of a "transformer" plus a "first inductor" and a "second inductor," and that the claim requires three structurally distinct (or at least conceptually separable) elements as depicted in the schematic diagrams '772 Patent, FIG. 2A

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement. The inducement allegation is based on Vicor allegedly encouraging customers to incorporate the accused converters into infringing systems (e.g., servers) through datasheets, technical materials, and direct customer support Compl. ¶54 The contributory infringement allegation posits that the accused converters are a material part of the invention, are not staple articles of commerce, and are known by Vicor to be specially adapted for an infringing use Compl. ¶55
• Willful Infringement: The complaint alleges willful infringement based on Vicor's alleged pre-suit knowledge of the '772 Patent. This knowledge is purportedly based on Vicor's status as a direct competitor, its alleged practice of monitoring Delta's patent portfolio, and the extensive history of patent litigation between the two companies, which allegedly necessitated investigation of Delta's patents Compl. ¶¶26-27 Compl. ¶¶29-34 The complaint alleges Vicor was aware of the patent at least as of January 2026 Compl. ¶34

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

1. A core technical question of mapping: Will discovery confirm that the internal circuitry of Vicor's accused converters mirrors the specific, multi-element architecture required by claim 4, particularly the unconventional capacitor connection between the high-voltage input and low-voltage output, and the precise composition of the magnetic assembly? The case may turn on this detailed element-by-element comparison.
2. A critical question of knowledge for willfulness: Will the court find that the extensive litigation history and alleged competitive monitoring between the parties gave Vicor actual, pre-suit knowledge of its alleged infringement of the '772 Patent, thus supporting the claim for enhanced damages? Or will Vicor successfully argue that its knowledge only attached upon service of this specific complaint?