Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes [X] No [ ]

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (Section 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes [X] No [ ]

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act (Check one): Large accelerated filer [X] Accelerated filer [ ] Non-accelerated filer [ ] Smaller reporting company [ ] Emerging growth company [ ]

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. Yes [ ] No [ ]

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes [ ] No [X]

As of AprilJuly 27, 2018, the registrant had outstanding 24,966,97525,080,569 shares of Common Stock, net of Treasury Shares.

LITTELFUSE, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

See accompanying Notes to Condensed Consolidated Financial Statements.

LITTELFUSE, INC.

CONDENSEDCONSOLIDATED STATEMENTS OF NET INCOME

(Unaudited)

See accompanying Notes to Condensed Consolidated Financial Statements.

LITTELFUSE, INC.

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

(Unaudited)

See accompanying Notes to Condensed Consolidated Financial Statements.

LITTELFUSE, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited)

See accompanying Notes to Condensed Consolidated Financial Statements.

Notes to Condensed Consolidated Financial Statements 

See Note 12, Segment Information for net sales by segment and countries.

Revenue Recognition

The Company recognizes revenue on product sales in the period in which the Company satisfies its performance obligation and control of the product is transferred to the customer. The Company’s sales arrangements with customers are predominately short term in nature and generally provide for transfer of control at the time of shipment as this is the point at which title and risk of loss of the product transfers to the customer. At the end of each period, for those shipments where title to the products and the risk of loss and rewards of ownership do not transfer until the product has been received by the customer, the Company adjusts revenues and cost of sales for the delay between the time that the products are shipped and when they are received by the customer. The amount of revenue recorded reflects the consideration to which the Company expects to be entitled in exchange for goods and may include adjustments for customer allowance, rebates and price adjustments. The Company’s distribution channels are primarily through direct sales and independent third-partythird-party distributors.

The Company has elected the practical expedient under ASC 340-40-25-4340-40-25-4 to expense commissions when incurred as the amortization period of the commission asset the Company would have otherwise recognized is less than one year.

Revenue and Billing

The Company generally accepts orders from customers through receipt of purchase orders or electronic data interchange based on written sales agreements and purchasing contracts. Contract pricing and selling agreement terms are based on market factors, costs, and competition. Pricing is often negotiated as an adjustment (premium or discount) from the Company’s published price lists. The customer is invoiced when the Company’s products are shipped to them in accordance with the terms of the sales agreement. As the Company’s standard payment terms are less than one year, the Company has elected the practical expedient under ASC 606-10-32-18606-10-32-18 to not assess whether a contract has a significant financing component. The Company also elected the practical expedient provided in ASC 606-10-25-18B606-10-25-18B to treat all product shipping and handling activities as fulfillment activities, and therefore recognize the gross revenue associated with the contract, inclusive of any shipping and handling revenue. This is similar to the Company’s prior practice and therefore the effect of the new guidance is immaterial.

Ship and Debit Program

Some of the terms of the Company’s sales agreements and normal business conditions provide customers (distributors) the ability to receive price adjustments on products previously shipped and invoiced. This practice is common in the industry and is referred to as a “ship and debit” program. This program allows the distributor to debit the Company for the difference between the distributors’ contracted price and a lower price for specific transactions. Under certain circumstances (usually in a competitive situation or large volume opportunity), a distributor will request authorization for pricing allowances to reduce its price. When the Company approves such a reduction, the distributor is authorized to “debit” its account for the difference between the contracted price and the lower approved price. The Company establishes reserves for this program based on historic activity and actual authorizations for the debit and recognizes these debits as a reduction of revenue.

Return to Stock 

The Company has a return to stock policy whereby certain customers, with prior authorization from Littelfuse management, can return previously purchased goods for full or partial credit. The Company establishes an estimated allowance for these returns based on historic activity. Sales revenue and cost of sales are reduced to anticipate estimated returns.

Volume Rebates

The Company offers volume based sales incentives to certain customers to encourage greater product sales. If customers achieve their specific quarterly or annual sales targets, they are entitled to rebates. The Company estimates the projected amount of rebates that will be achieved by the customer and recognizes this estimated cost as a reduction to revenue as products are sold.

Recently Adopted Accounting Standards

In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No.2017-07 2017-07 “Compensation-Retirement Benefits (Topic 715)715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-Retirement Benefit Cost,” which changed the presentation of net periodic pension and post-retirement benefit cost (net benefit cost) within the Statement of Income. Under the previous guidance, net benefit cost was reported as an employee cost within operating income. The amendment required the bifurcation of net benefit cost, with the service cost component to be presented with other employee compensation costs in operating income while the other components will be reported separately outside of income from operations. ASU No.2017-07 2017-07 was effective for the first quarter of 2018 with the Company adopting the new standard on December 31, 2017.

In January 2016, the FASB issued ASU No.2016-01, 2016-01, “Financial Instruments-Recognition and Measurement of Financial Assets and Financial Liabilities” which addressed certain aspects of the recognition, measurement, presentation and disclosure of financial instruments. The ASU requires the Company to recognize any changes in the fair value of certain equity investments in net income. Previously these changes were recognized in other comprehensive income ("OCI"). The Company adopted the new standard on December 31, 2017, on a modified retrospective basis, recognizing the cumulative effect as a $9.8$9.8 million increase to retained earnings. As a result of the adoption of the new standard and change in fair value of our equity investments, for the threesix months ended March 31,June 30, 2018, the Company recognized an unrealized gain of $1.9$2.8 million in Other (income) expense, net in the Condensed Consolidated Statements of Net Income.

In May 2014, the FASB issued ASU No.2014-09, 2014-09, “Revenue from Contracts with Customers” (Topic 606)606) which supersedes the revenue recognition requirements in ASC 605, “Revenue Recognition.” This ASU provides a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and will supersede most current revenue recognition guidance. The guidance permits two implementation approaches, one requiring retrospective application of the new standard with restatement of prior years and one requiring prospective application of the new standard with disclosure of results under old standards. The Company adopted the new standard on December 31, 2017 using the modified retrospective method, however, no adjustment to retained earnings was needed. The new guidance did not have a material effect on the Company’s Condensed Consolidated Statements of Income. See the Revenue Recognition section above for further discussion.

In October 2016, the FASB issued ASU No.2016-16, 2016-16, "Income Taxes” (Topic 740)740). This ASU update requires entities to recognize the income tax consequences of many intercompany asset transfers at the transaction date. The seller and buyer will immediately recognize the current and deferred income tax consequences of an intercompany transfer of an asset other than inventory. The tax consequences were previously deferred. The Company adopted the new standard on December 31, 2017 and it did not have a material impact.

Recently Issued Accounting Standards

In February 2016, the FASB issued ASU No.2016-02, 2016-02, "Leases" (Topic 842)842). This ASU requires lessees to recognize, on the balance sheet, assets and liabilities for the rights and obligations created by leases of greater than twelve months. The accounting by lessors will remain largely unchanged. The ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. Adoption will require a modified retrospective transition. The Company will adopt the standard in the first quarter of 2019. The Company is currently evaluatinghas made progress on assessing the Company’s portfolio of leases and compiling a central repository of all active leases. We are in the process of assessing the design of the future lease process and drafting a policy to address the new standard requirements. Key lease data elements are being evaluated including developing a methodology for determining the incremental borrowing rate across all countries where we have operations. While the Company has not yet completed its evaluation of the impact the new lease accounting standard will have on its Consolidated Financial Statements, the Company expects to recognize right of ASU 2016-02.use assets and lease liabilities for its operating leases in the Consolidated Balance Sheet upon adoption.

In January 2018, the FASB released guidance on the accounting for tax on the global intangible low-taxed income ("GILTI") provisions inof the 2017 U.S. Tax Act.Cuts and Jobs Act (the “Tax Act”). The GILTI provisions impose a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations. The guidance indicates that either accounting for deferred taxes related to GILTI inclusions or treating any taxes on GILTI inclusions as period cost are both acceptable methods subject to an accounting policy election. The Company has not yet completed its assessment and therefore has not yet elected an accounting policy.

In February 2018, the FASB issued ASU No.2018-02 2018-02 “Income Statement—Reporting Comprehensive Income (Topic 220)220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which permits the reclassification of tax effects stranded in accumulated other comprehensive income to retained earnings as a result of the Tax Act. The standard also requires entities to disclose whether or not they elected to reclassify the tax effects related to the Tax Act as well as their policy for releasing income tax effects from accumulated other comprehensive income. The standard allows the option of applying either a retrospective adoption, meaning the standard is applied to all periods in which the effect of the Tax Act is recognized, or applying the amendments in the period of adoption, meaning an adjustment is made to shareholder’s equity as of the beginning of the reporting period. ASU 2018-022018-02 will be effective in the first quarter of 2019; however early adoption is permitted for interim and annual periods, including the reporting period in which the Tax Act was enacted. The Company is currently evaluating the impact of ASU 2018-022018-02 on the Consolidated Financial Statements.

Included in IXYS’s current assets, net was approximately $49.1$49.1 million of receivables. All IXYS goodwill, other assets and liabilities were recorded in the Electronics segment and primarily reflected in the Americas and European geographic areas. The goodwill resulting from this acquisition consists largely of the Company’s expected future product sales and synergies from combining IXYS’s products and technology with the Company’s existing electronics product portfolio. Goodwill resulting from the IXYS acquisition is not expected to be deductible for tax purposes.

Included in the Company’s Condensed Consolidated Statements of Net Income for the three and six months ended March 31,June 30, 2018 are net sales of approximately $86.3$100.2 million and $186.5 million, respectively and a loss before income taxes of approximately $17.8$13.9 million and $31.7 million, respectively since the January 17, 2018 acquisition of IXYS. The Company recognized approximately $5.9$1.6 million and $7.5 million of stock compensation expense related to IXYS stock options converted to Littelfuse stock options during the three and six months ended March 31,June 30, 2018, of which $4.5$4.5 million was recognized immediately as it related to prior services periods.

As required by purchase accounting rules, the Company recorded a $36.9$36.9 million step-up of inventory to its fair value as of the acquisition date based on the preliminary valuation. The step-up is beingwas amortized as a non-cash charge to cost of goods sold during the first and second quarters of 2018, as the acquired inventory iswas sold, and reflected as other non-segment costs. During the three and six months ended March 31,June 30, 2018, the Company recognized a charge of $17.9$19.0 million and $36.9 million, respectively, for the amortization of this fair value inventory step-up.

During the three and six months ended March 31,June 30, 2018, the Company incurred approximately $10.2$0.8 million and $11.0 million, respectively, of legal and professional fees related to this acquisition which were primarily recognized as selling, general, and administrative expenses. These costs were reflected as other non-segment costs.

20172017 Acquisitions

U.S. Sensor

On July 7, 2017, the Company acquired the assets of U.S. Sensor Corporation (“U.S. Sensor”). The acquisition purchase price of $24.3$24.3 million, net of the finalization of an income tax gross up which was settled in the fourth quarter of 2017, was funded with available cash. The acquired business expands the Company’s existing sensor portfolio in several key electronics and industrial end markets. U.S. Sensor manufactures a variety of high quality negative temperature coefficient thermistors as well as thermistor probes and assemblies. Product lines also include thin film platinum resistance temperature detectors (“RTDs”) and RTD assemblies.

The following table summarizes the purchase price allocation of the fair value of assets acquired and liabilities assumed in the U.S. Sensor acquisition:

Included in U.S. Sensor’s current assets, net was approximately $1.5$1.5 million of receivables. All U.S. Sensor goodwill, other assets and liabilities were recorded in the Electronics segment and reflected in the United States geographic area. The goodwill resulting from this acquisition consists largely of the Company’s expected future product sales and synergies from combining U.S. Sensor’s products and technology with the Company’s existing electronics product portfolio. Goodwill for the above acquisition is expected to be deductible for tax purposes.

As required by purchase accounting rules, the Company recorded a $1.6$1.6 million step-up of inventory to its fair value as of the acquisition date based on the preliminary valuation. The step-up was amortized as a non-cash charge to cost of goods sold during the third quarter of 2017, as the acquired inventory was sold, and reflected as other non-segment costs.

Monolith

In December 2015, the Company invested $3.5$3.5 million in the preferred stock of Monolith Semiconductor Inc. (“Monolith”), a U.S. start-up Company developing silicon carbide technology, which represented approximately 12% of the common stock of Monolith on an as-converted basis. The Company accounted for its investment in Monolith under the cost method with any changes in value recorded in other comprehensive income. The value of the Monolith investment was $3.5$3.5 million at December 31, 2016.

On February 28, 2017, pursuant to a Securities Purchase Agreement between the Company and the stockholders of Monolith (“Securities Purchase Agreement”) and conditioned on Monolith achieving a product development milestone and other provisions, the Company acquired 62% of the outstanding common stock of Monolith for $15$15 million. The Securities Purchase Agreement includes provisions whereby the Company will acquire the remaining outstanding stock of Monolith (“non-controlling interest”) at a time or times based on Monolith meeting certain technical and sales targets. During the first quarter of 2018, Monolith met the next set of technical and sales targets. As a result, and pursuant to the Securities Purchase Agreement, in April 2018 the Company acquired an additional 19% of the outstanding common stock of Monolith for $5 million.$5 million, of which $4 million was paid to the stockholders of Monolith. Consideration for the purchase of the remaining 19% outstanding common stock will be either $0.5$0.5 million or $5$5 million, based on Monolith meeting the remaining technical and sales targets, and will be paid no later than June 30, 2019.

The additional investment, in the first quarter of 2017, resulted in the Company gaining control of Monolith and was accounted for as a step-acquisition with the fair value of the original investment immediately before the acquisition estimated to be approximately $3.5$3.5 million. As the fair value of the investment immediately prior to the transaction equaled the carrying value, there was no impact on the Company’s Consolidated Statements of Net Income. As the Securities Purchase Agreement includes an obligation of the Company to mandatorily redeem the non-controlling interest for cash, the fair value of the non-controlling interest was recognized as a liability on the Company’s Consolidated Balance Sheets. The original investment of $3.5$3.5 million, additional cash consideration of $14.2$14.2 million (net of cash acquired), and the non-cash consideration of the fair value of the commitment to purchase the non-controlling interest of $9.0$9.0 million resulted in a purchase price of $26.7$26.7 million. Changes in the fair value of the non-controlling interest are recognized in the Company’s Consolidated Statements of Net Income.

Commencing March 1, 2017, Monolith was reflected as a consolidated subsidiary within the Company’s Consolidated Financial Statements. Had the acquisition occurred as of January 1,2017, the impact on the Company’s consolidated results of operations would not have been material.

The following table summarizes the purchase price allocation of the fair value of assets acquired and liabilities assumed in the Monolith acquisition:

Included in Monolith’s current assets, net was approximately $0.7$0.7 million of receivables. All Monolith goodwill, other assets and liabilities were recorded in the Electronics segment and reflected in the United States geographic area. The goodwill resulting from this acquisition consists largely of the Company’s expected future product sales and synergies from combining Monolith’s products and technology with the Company’s existing electronics product portfolio. Goodwill for the above acquisition is not expected to be deductible for tax purposes.

Pro Forma Results

The following table summarizes, on a pro forma basis, the combined results of operations of the Company and IXYS as though the acquisition had occurred as of January 1, 2017. The Company has not included pro forma results of operations for U.S. Sensor or Monolith as these results were not material to the Company. The pro forma amounts presented are not necessarily indicative of either the actual consolidated results had the IXYS acquisition occurred as of January 1, 2017 or of future consolidated operating results.

Pro forma results presented above primarily reflect the following adjustments:

The components of other intangible assets at March 31,June 30, 2018 are as follows:

During the threesix months ended March 31,June 30, 2018, the Company recorded additions to other intangible assets of $211.6$212.7 million, related to the IXYS acquisition, the components of which were as follows:

During the three and six months ended March 31,June 30, 2018 and AprilJuly 1, 2017, the Company recorded amortization expense of $12.0$13.4 million and $5.9$6.2 million and $25.4 million and $12.1 million, respectively for intangible assets with definite lives.

Estimated annual amortization expense related to intangible assets with definite lives as of March 31,June 30, 2018 is as follows:

Revolving Credit Facility / Term Loan

On March 4, 2016, the Company entered into a five-yearfive-year credit agreement (“Credit Agreement”) with a group of lenders for up to $700.0$700.0 million. The Credit Agreement consisted of an unsecured revolving credit facility (“Revolving Credit Facility”) of $575.0$575.0 million and an unsecured term loan credit facility (“Term Loan”) of up to $125.0$125.0 million. In addition, the Company had the ability, from time to time, to increase the size of the Revolving Credit Facility and the Term Loan by up to an additional $150.0$150.0 million, in the aggregate, in each case in minimum increments of $25.0$25.0 million, subject to certain conditions and the agreement of participating lenders. For the Term Loan, the Company was required to make quarterly principal payments of $1.6 million through March 31, 2018 and $3.1 million from June 30, 2018 through December 31, 2020 with the remaining balance due on March 4, 2021.

On October 13, 2017, the Company amended the Credit Agreement to increase the Revolving Credit Facility from $575.0$575.0 million to $700.0$700.0 million and increase the Term Loan from $125.0$125.0 million to $200.0$200.0 million and to extend the expiration date from March 4, 2021 to October 13, 2022. The Credit Agreement also includes the option for the Company to increase the size of the Revolving Credit Facility and the Term Loan by up to an additional $300.0$300.0 million, in the aggregate, subject to the satisfaction of certain conditions set forth in the Credit Agreement. Term Loans may be made in up to two advances. The first advance of $125.0$125.0 million occurred on October 13, 2017 and the second advance of $75.0$75.0 million occurred on January 16, 2018. For the Term Loan, the Company is required to make quarterly principal payments of 1.25% of the original term loan ($($2.5 million with the second advance on January 16, 2018) through maturity, with the remaining balance due on October 13, 2022. In addition to the quarterly principal payments, the Company paid $35.0 million of principal on the term loan during the three months ended June 30, 2018.

Outstanding borrowings under the Credit Agreement bear interest, at the Company’s option, at either LIBOR, fixed for interest periods of one, two, three or six-monthsix-month periods, plus 1.00% to 2.00%, or at the bank’s Base Rate, as defined, plus 0.00% to 1.00%, based upon the Company’s Consolidated Leverage Ratio, as defined. The Company is also required to pay commitment fees on unused portions of the credit agreement ranging from 0.15% to 0.25%, based on the Consolidated Leverage Ratio, as defined.defined in the agreement. The credit agreement includes representations, covenants and events of default that are customary for financing transactions of this nature. The effective interest rate on outstanding borrowings under the credit facility was 3.13%3.59% at March 31,June 30, 2018.

As of March 31,June 30, 2018, the Company had $0.1$0.1 million outstanding in letters of credit and had available $696.9$699.9 million of borrowing capacity under the Revolving Credit Facility. At March 31,June 30, 2018, the Company was in compliance with all covenants under the Credit Agreement.

Senior Notes

On December 8, 2016, the Company entered into a Note Purchase Agreement, pursuant to which the Company issued and sold €212€212 million aggregate principal amount of senior notes in two series. The funding date for the Euro denominated senior notes occurred on December 8, 2016 for €117€117 million in aggregate amount of 1.14% Senior Notes, Series A, due December 8, 2023 (“(“Euro Senior Notes, Series A due 2023”), and €95€95 million in aggregate amount of 1.83% Senior Notes, Series B due December 8, 2028 (“(“Euro Senior Notes, Series B due 2028”) (together, the “Euro Senior Notes”). Interest on the Euro Senior Notes is payable semiannually on June 8 and December 8, commencing June 8, 2017.

On December 8, 2016, the Company entered into a Note Purchase Agreement, pursuant to which the Company issued and sold $125$125 million aggregate principal amount of senior notes in two series. On February 15, 2017, $25$25 million in aggregate principal amount of 3.03% Senior Notes, Series A, due February 15, 2022 (“(“U.S. Senior Notes, Series A due 2022”), and $100$100 million in aggregate principal amount of 3.74% Senior Notes, Series B, due February 15, 2027 (“(“U.S. Senior Notes, Series B due 2027”) (together, the “U.S. Senior Notes due 2022 and 2027”) were funded. Interest on the U.S. Senior Notes due 2022 and 2027 is payable semiannually on February 15 and August 15, commencing August 15, 2017.

On November 15, 2017, the Company entered into a Note Purchase Agreement pursuant to which the Company issued and sold $175$175 million in aggregate principal amount of senior notes in two series. On January 16, 2018, $50$50 million aggregate principal amount of 3.48% Senior Notes, Series A, due February 15, 2025 (“(“U.S. Senior Notes, Series A due 2025”) and $125$125 million in aggregate principal amount of 3.78% Senior Notes, Series B, due February 15, 2030 (“(“U.S. Senior Notes, Series B due 2030”) (together the “U.S. Senior Notes due 2025 and 2030” and with the Euro Senior Notes and the U.S. Senior Notes 2022 and 2027, the “Senior Notes”) were funded. Interest on the U.S. Senior Notes due 2025 and 2030 will be payable on February 15 and August 15, commencing on August 15, 2018.

The Senior Notes have not been registered under the Securities Act, or applicable state securities laws. The Senior Notes are general unsecured senior obligations and rank equal in right of payment with all existing and future unsecured unsubordinated indebtedness of the Company.

The Senior Notes are subject to certain customary covenants, including limitations on the Company’s ability, with certain exceptions, to engage in mergers, consolidations, asset sales and transactions with affiliates, to engage in any business that would substantially change the general business of the Company, and to incur liens. In addition, the Company is required to satisfy certain financial covenants and tests relating to, among other matters, interest coverage and leverage. At March 31,June 30, 2018, the Company was in compliance with all covenants under the Senior Notes.

The Company may redeem the Senior Notes upon the satisfaction of certain conditions and the payment of a make-whole amount to noteholders, and are required to offer to repurchase the Senior Notes at par following certain events, including a change of control.