UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of report (Date of earliest event reported): October 24, 2013

SILICON LABORATORIES INC.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (512) 416-8500

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 2.02. Results of Operations and Financial Condition

On October 24, 2013, Silicon Laboratories Inc. (“Silicon Laboratories”) issued a press release describing its results of operations for its fiscal quarter ended September 28, 2013.  A copy of the press release is attached as Exhibit 99 to this report.

Item 9.01. Financial Statements and Exhibits

(d) Exhibits.

99                    Press Release of Silicon Laboratories Inc. dated October 24, 2013

Use of Non-GAAP Financial Information

From time to time, Silicon Laboratories provides certain non-GAAP financial measures as additional information relating to its operating results.  The non-GAAP financial measurements provided in the press release furnished herewith do not replace the presentation of Silicon Laboratories’ GAAP financial results. These additional measurements merely provide supplemental information to assist investors in analyzing Silicon Laboratories’ financial position and results of operations; however, these measures are not in accordance with, or an alternative to, GAAP and may be different from non-GAAP measures used by other companies. Silicon Laboratories has chosen to provide this information to investors because it believes that such supplemental information enables them to perform meaningful comparisons of past, present and future operating results, and as a means to highlight the results of core ongoing operations.

Pursuant to the requirements of Regulation G, we have provided in the press release furnished with this report a reconciliation of the non-GAAP financial measures to the most directly comparable GAAP financial measures.

The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section.  The information contained therein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission made by Silicon Laboratories, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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EXHIBIT INDEX

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Exhibit 99

SILICON LABS ANNOUNCES THIRD QUARTER 2013 RESULTS

— Record Revenue for Broadcast Video and Solid Results for Broad-based Products —

AUSTIN, Texas — Oct. 24, 2013 — Silicon Labs (NASDAQ: SLAB), a leader in high-performance, analog-intensive, mixed-signal integrated circuits (ICs), today reported financial results for its third quarter ended Sept. 28, 2013. Overall revenue in the third quarter was $146.9 million, an increase of 3.8 percent sequentially and a 1.7 percent decrease compared with the same period a year ago.

Financial Highlights

On a GAAP basis, gross margins were 60.0 percent. GAAP R&D investment increased on a sequential basis and year over year to $40.7 million. GAAP SG&A expenses increased both sequentially and year over year to $37.0 million. Resulting GAAP operating income as a percentage of revenue decreased both sequentially and year over year to 7.1 percent. GAAP diluted earnings per share were $0.15, down 48.3 percent sequentially and down 37.5 percent year over year due primarily to Energy Micro acquisition-related items.

The non-GAAP results exclude the impact of stock compensation, amortization from acquired intangible assets and certain other items as set forth in the reconciliation table below. Non-GAAP gross margins decreased sequentially to 61.1 percent. On a non-GAAP basis, R&D expenses increased to $33.7 million, and SG&A expenses increased to $29.8 million. Non-GAAP operating income in the quarter was 17.9 percent. Non-GAAP diluted earnings per share in the quarter were $0.45, down sequentially and year over year.

Business Highlights

Silicon Labs reported record revenue for Broadcast video products and solid performance for microcontroller (MCU) and timing products. Revenue from Broad-based products, which include MCU, timing, power and sensor products, represented 50 percent of total revenue in the third quarter, up 6.5 percent sequentially.

The company continues to expand its position in the Internet of Things (IoT) market with solid design win activity in home automation, smart energy and smart metering applications. Silicon Labs completed its first quarter with Energy Micro as a key part of the company. The teams and operational systems are fully integrated, and the product development roadmaps are aligned to enable the next generation of energy-friendly microcontrollers and radios. During the quarter, Silicon Labs introduced a new family of 8-bit MCUs optimized for cost-sensitive motor control and industrial applications.

Revenue from Broadcast products, including audio and video tuner product lines, represented 35 percent of total revenue in the third quarter and delivered another growth quarter.

In the third quarter, Silicon Labs introduced a new family of TV tuners offering the industry’s highest performance and integration, as well as lowest system cost. These TV tuners are based on five generations of patented architectural enhancements and a production history of more than 200 million silicon tuners shipped to date, solidifying Silicon Labs’ No. 1 position in the video tuner market. Continuing to diversify its Broadcast video revenue, the company also announced the world’s most advanced digital video broadcast (DVB) demodulators for TVs and set-top boxes.

“We achieved record revenue in the third quarter for our industry-leading Broadcast video products, as well as solid results for our Broad-based products,” said Tyson Tuttle, CEO of Silicon Labs. “The integration of Energy Micro further strengthens our Broad-based portfolio and our leadership position in low-energy MCU solutions for the Internet of Things.”

The company expects revenue for the fourth quarter to be in the range of $140 million to $145 million, with declines in Broadcast video reflecting weak end-customer demand and pronounced seasonality.

Webcast and Conference Call

A conference call discussing the quarterly results will follow this press release at 7:30 a.m. Central time. An audio webcast will be available simultaneously on Silicon Labs’ website under Investor Relations (www.silabs.com). A replay will be available after the call at the same website listed above or by calling 1 (855) 859-2056 or (404) 537-3406 (international) and by entering 39717386. The replay will be available through Nov. 24.

About Silicon Labs

Silicon Labs is an industry leader in the innovation of high-performance, analog-intensive, mixed-signal ICs. Developed by a world-class engineering team with unsurpassed expertise in mixed-signal design, Silicon Labs’ diverse portfolio of patented semiconductor solutions offers customers significant advantages in performance, size and power consumption. For more information about Silicon Labs, please visit www.silabs.com.

Forward-Looking Statements

This press release contains forward-looking statements based on Silicon Labs’ current expectations. The words “believe,” “estimate,” “expect,” “intend,” “anticipate,” “plan,” “project,” “will” and similar phrases as they relate to Silicon Labs are intended to identify such forward-looking statements. These forward-looking statements reflect the current views and assumptions of Silicon Labs and are subject to various risks and uncertainties that could cause actual results to differ materially from expectations. Among the factors that could cause actual results to differ materially from those in the forward-looking statements are the following: risks that Silicon Labs may not be able to maintain its historical growth; quarterly fluctuations in revenues and operating results; difficulties developing new products that achieve market acceptance; dependence on a limited number of products and customers; intellectual property litigation risks; risks associated with acquisitions and divestitures; product liability risks; difficulties managing our distributors, manufacturers and subcontractors; inventory-related risks; difficulties managing international activities; risks that Silicon Labs may not be able to manage strains associated with its growth; credit risks associated with our accounts receivable; dependence on key personnel; stock price volatility; geographic concentration of manufacturers, assemblers, test service providers and customers in Asia that subjects Silicon Labs’ business and results of operations to risks of natural disasters, epidemics, war and political unrest; debt-related risks; capital-raising risks; the competitive and cyclical nature of the semiconductor industry; average selling prices of products may decrease significantly and rapidly; information technology risks; conflict mineral risks and other factors that are detailed in the SEC filings of Silicon Laboratories Inc. Silicon Labs disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. References in this press release to Silicon Labs shall mean Silicon Laboratories Inc.

Note to editors: Silicon Laboratories, Silicon Labs and the Silicon Labs logo are trademarks of Silicon Laboratories Inc. All other product names noted herein may be trademarks of their respective holders.

CONTACT: Deborah Stapleton, +1 650.470.4200, Deborah.Stapleton@silabs.com

Silicon Laboratories Inc.

Condensed Consolidated Statements of Income

(In thousands, except per share data)

(Unaudited)

Unaudited Reconciliation of GAAP to Non-GAAP Financial Measures

(In thousands, except per share data)

Silicon Laboratories Inc.

Condensed Consolidated Balance Sheets

(In thousands, except per share data)

(Unaudited)

Silicon Laboratories Inc.

Condensed Consolidated Statements of Cash Flows

(In thousands)

(Unaudited)

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