LITTELFUSE INC /DE

Evaluation of Disclosure Controls and Procedures

The Company maintains disclosure controls and procedures that are designed to ensure that information required to be disclosed in its reports filed under the Securities Exchange Act of 1934, as amended, is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms and that such information is accumulated and communicated to management, including the Company’s Chief Executive Officer and Chief Financial Officer, as appropriate, to allow for timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, the Company recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives, and the Company is required to apply its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

As required by SEC Rule 15d-15(b), the Company carried out an evaluation, under the supervision and with the participation of its management, including the Chief Executive Officer and Chief Financial Officer, of the effectiveness of the design and operation of its disclosure controls and procedures pursuant to SEC Rule 13a-15 and based upon the updated framework in Internal Control — Integrated Framework (2013), as of the end of the period covered by this Annual Report on Form 10-K. The Company’s Chief Executive Officer and Chief Financial Officer concluded that the Company’s disclosure controls and procedures were effective as of December 27, 2025.

Management’s Report on Internal Control over Financial Reporting

Section 404 of the Sarbanes-Oxley Act of 2002 requires management to include in this Annual Report on Form 10-K a report on management’s assessment of the effectiveness of the Company’s internal control over financial reporting, as well as an attestation report from the Company’s independent registered public accounting firm on the effectiveness of the Company’s internal control over financial reporting. Management is responsible for establishing and maintaining adequate internal control over financial reporting as such term is defined in Exchange Act Rule 13a-15(f) and 15d-15(f), based on the criteria established in Internal Control-Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway

Commission (“the COSO Framework). The Company’s internal control system was designed to provide reasonable assurance to its management and the Board of Directors regarding the preparation and fair presentation of published financial statements.

The Company’s management, including its Principal Executive Officer and Principal Financial Officer, assessed the effectiveness of the Company’s internal control over financial reporting as of December 27, 2025, based upon the updated framework in Internal Control — Integrated Framework (2013). Based on this assessment, the Company’s management concluded that, as of December 27, 2025, the Company’s internal control over financial reporting was effective.

On December 11, 2025, the Company completed the acquisition of Basler, as discussed in Note 2 – Acquisitions. Management has excluded Basler's internal controls over financial reporting from its assessment of the effectiveness of internal controls over financial reporting as of December 27, 2025. Basler’s net sales and total assets represent approximately 0.2% and 9%, respectively, of the consolidated financial statement amounts as of and for the fiscal year ended, December 27, 2025.

The Company’s independent registered public accounting firm, Deloitte & Touche LLP, has audited the consolidated financial statements included in this Annual Report on Form 10-K issued and have issued an attestation report on our internal control over financial reporting as of December 27, 2025.

Changes in Internal Control over Financial Reporting

During the fiscal year of 2025, the Company completed a number of initiatives and actions to address the previously reported material weaknesses, which included the following:

Control Environment

•The Company replaced key finance and operational roles at certain non-U.S. manufacturing locations, and recruited personnel with appropriate internal controls experience and accounting knowledge commensurate with our accounting and reporting requirements;

•The Company completed the redesign of the regional operations and finance organizational structures; and

•New corporate policies and procedures have been adopted and disseminated along with appropriate training provided to strengthen the control environment and inventory management oversight.

Control Activities

•Key monitoring controls have been designed and implemented for full physical counts, inventory storage locations, and over the completeness and accuracy of excessive and obsolete inventory calculations; and

•Full physical inventory observations, facilitated by independent counters, have been performed in certain non-U.S. locations in the second, third and fourth quarters of the fiscal year 2025.

After implementing the above initiatives and actions, the Company completed the necessary testing and concluded that the material weaknesses outlined above have been remediated as of December 27, 2025.

Other than the changes described above to address and remediate the previously disclosed material weaknesses, there has been no change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Inherent Limitations on Effectiveness of Controls and Procedures

There are inherent limitations to the effectiveness of any system of internal control over financial reporting. Accordingly, even an effective system of internal control over financial reporting can only provide reasonable assurance with respect to financial statement preparation and presentation in accordance with accounting principles generally accepted in the United States of America. Our internal controls over financial reporting are subject to various inherent limitations, including cost limitations, judgments used in decision making, assumptions about the likelihood of future events, the soundness of our systems, and the possibility of human error, and the risk of fraud. Moreover, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may be inadequate because of changes in conditions and the risk that the degree of compliance with policies or procedures may deteriorate over time.