Celebration IP LLC v. Maxim Integrated Products Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Celebration IP LLC (Texas)
  • Defendant: Maxim Integrated Products, Inc. (Delaware)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 3:20-cv-01018, N.D. Tex., 04/24/2020
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has committed acts of patent infringement in the district and maintains an established place of business in the district.
• Core Dispute: Plaintiff alleges that Defendant’s integrated circuit products infringe a patent related to a discharge control circuit for batteries.
• Technical Context: The technology concerns circuits designed to prevent the over-discharge of batteries, a critical function for extending the life and ensuring the safety of portable electronic devices.
• Key Procedural History: The complaint does not mention any prior litigation, inter partes review (IPR) proceedings, or licensing history related to the patent-in-suit.

Case Timeline

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

U.S. Patent No. 6,346,795 - "Discharge control circuit of batteries"

• Patent Identification: U.S. Patent No. 6,346,795, "Discharge control circuit of batteries," issued February 12, 2002.

The Invention Explained

• Problem Addressed: The patent addresses a problem in conventional battery protection circuits where, after a discharge is cut off due to low voltage, the battery's cell voltage can instantaneously recover. This voltage "bounce" can cause the protection circuit to mistakenly re-enable discharge, leading to repeated on-off cycling that can damage the battery or cause "malfunctions of the load circuit" (’795 Patent, col. 3:49-65).
• The Patented Solution: The invention introduces a control circuit with a "switch holding circuit" that ensures the discharge remains cut off for a predetermined time, even if the cell voltage recovers above the initial cutoff threshold (’795 Patent, Abstract). This is accomplished, for example, by using a hysteresis buffer that has a higher voltage threshold for turning discharge off than the lower threshold required to turn it back on, creating a "dead band" that ignores the temporary voltage recovery (’795 Patent, col. 5:48-64; Fig. 5).
• Technical Importance: This approach provides a more stable and secure method for preventing battery over-discharge, avoiding the unstable cycling that could occur with simpler voltage-monitoring circuits (’795 Patent, col. 7:29-37).

Key Claims at a Glance

• The complaint asserts infringement of "one or more claims" without specifying them (Compl. ¶11). Independent claim 1 is representative:
  • A discharge control circuit for controlling discharge of a battery including at least one cell comprising:
  • a discharge control switch connected to the battery for cutting off a discharge current of the battery in response to a discharge stop signal; and
  • a control circuit connected to the battery and the discharge control switch for generating the discharge stop signal that deactivates the discharge control switch when a voltage of at least one cell reaches a lower limit,
  • wherein the control circuit includes a switch holding circuit for continuously supplying the discharge stop signal to the discharge control switch for a predetermined time after the discharge stop signal is generated.

III. The Accused Instrumentality

Product Identification

• The complaint accuses "Exemplary Defendant Products" which it states are identified in charts incorporated into the complaint and attached as Exhibit 2 (Compl. ¶¶11, 17-18). This exhibit was not filed with the complaint.

Functionality and Market Context

• The complaint does not provide sufficient detail for analysis of the accused products' specific functionality or market context beyond the general allegation that they are integrated circuits used in battery management systems.

IV. Analysis of Infringement Allegations

The complaint references claim charts in an unfiled Exhibit 2 (Compl. ¶18). It alleges that the "Exemplary Defendant Products practice the technology claimed by the '795 Patent" and "satisfy all elements of the Exemplary '795 Patent Claims" (Compl. ¶17). However, the complaint itself does not contain specific factual allegations mapping claim elements to accused product features. A claim chart table cannot be constructed from the provided documents.

No probative visual evidence provided in complaint.

• Identified Points of Contention:
  • Scope Questions: A primary question will be whether the accused products, once identified, contain a component that meets the definition of the claimed "switch holding circuit." The dispute may center on whether the accused circuits' method for preventing premature re-activation of discharge is structurally and functionally the same as that claimed.
  • Technical Questions: A key evidentiary question will be whether the accused circuits "continuously" supply a "discharge stop signal" for a "predetermined time" after a low-voltage event is detected, as required by claim 1. The specific mechanism and timing of the accused circuits' operation will be central to this inquiry.

V. Key Claim Terms for Construction

• The Term: "switch holding circuit"
• Context and Importance: This term appears in independent claim 1 and describes the core inventive concept for solving the voltage-recovery problem. The scope of this term will likely be case-dispositive, as it distinguishes the invention from prior art that may have lacked a mechanism to prevent premature discharge resumption.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language itself is largely functional, describing a circuit that performs the function of "continuously supplying the discharge stop signal... for a predetermined time" (’795 Patent, col. 10:38-42). Plaintiff may argue this functional definition is not limited to any specific structure and covers any circuit that achieves this result.
  • Evidence for a Narrower Interpretation: Defendant may argue the term should be construed more narrowly in light of the specific embodiments disclosed in the specification. These include a "hysteresis buffer" (16) (’795 Patent, col. 5:48-54) and a "second latch circuit" (19) (’795 Patent, col. 11:21-28), which a court could find limit the scope of the claimed functional language.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, asserting Defendant sells the accused products to customers for infringing uses and distributes "product literature and website materials" that instruct on such use (Compl. ¶¶14-15). It also alleges contributory infringement, claiming the products are not a "staple article of commerce suitable for substantial noninfringing use" (Compl. ¶16).
• Willful Infringement: The complaint does not use the term "willful," but it establishes a basis for post-suit enhancement of damages by alleging that "service of this Complaint... constitutes actual knowledge" and that Defendant continues to infringe despite this knowledge (Compl. ¶¶13-14).

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

1. Evidentiary Sufficiency: A threshold issue is the lack of specificity in the complaint. The case cannot meaningfully proceed until Plaintiff identifies the specific accused products and provides concrete evidence of how their circuitry allegedly maps to the patent's claims, a step typically accomplished through infringement contentions.

2. Claim Construction of "switch holding circuit": The central legal battle will likely be over the definition of the "switch holding circuit." The case may turn on whether this term is given a broad, functional construction covering modern battery management techniques, or a narrower construction limited to the specific circuit diagrams disclosed in the patent, such as the hysteresis buffer embodiment.