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): September 20, 2006

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 7.01. Regulation FD Disclosure

On September 20, 2006, Silicon Laboratories Inc. (“Silicon Laboratories”) issued a press release revising its revenue and earnings per share guidance for its fiscal quarter ending September 30, 2006.  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 September 20, 2006.

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.

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.

EXHIBIT INDEX

Exhibit 99

SILICON LABORATORIES REVISES REVENUE OUTLOOK FOR THE THIRD QUARTER

AUSTIN, Texas – Sept. 20, 2006 – Silicon Laboratories Inc. (Nasdaq: SLAB) today announced that it is revising its revenue outlook for the third quarter of fiscal 2006, which ends on September 30, 2006.  The company now anticipates that revenue for the third quarter will be in the range of $113 to $116 million.  The company previously announced that it expected third quarter revenue would be in the range of $122 to $127 million.

Revised third quarter expectations for the mobile handset business include both weaker than expected demand for Aero® transceivers due to prolonged inventory adjustments in China and lower than anticipated sales to some ODMs due to demand shifts at their OEM customers. The broad-based mixed-signal business is also expected to be down slightly sequentially due to weaker than expected analog modem demand.

The company also revised third quarter earnings per share guidance. Diluted net income per share on a GAAP basis is expected to be $0.05 to $0.08. Non-GAAP third quarter diluted net income per share is expected to be $0.22 to $0.25.  This excludes anticipated non-cash charges of $0.14 for stock compensation expense and approximately $0.03 for the in process R&D write-off from the StackCom acquisition.

Silicon Laboratories’ third quarter financial announcement and conference call are scheduled for October 23rd, at which time the company will discuss results in more detail as well as the outlook for the fourth quarter of fiscal 2006.

About Silicon Laboratories Inc.

Silicon Laboratories Inc. is a leading designer of high-performance, analog-intensive, mixed-signal integrated circuits (ICs) for a broad range of applications.  Silicon Laboratories’ diverse portfolio of highly integrated, patented solutions is developed by a world-class engineering team with decades of cumulative expertise in cutting-edge mixed-signal design.  The company has design, engineering, marketing, sales and applications offices throughout North America, Europe and Asia. For more information about Silicon Laboratories please visit www.silabs.com.

Cautionary Language

This press release contains forward-looking statements based on Silicon Laboratories’ current expectations. The words “believe,” “estimate,” “expect,” “intend,” “anticipate,” “plan,” “project,” “will” and similar phrases as they relate to Silicon Laboratories are intended to identify such forward-looking statements. These forward-looking statements reflect the current views and assumptions of Silicon Laboratories 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 Laboratories may not be able to maintain its historical growth; quarterly fluctuations in revenues and operating results; volatile stock price; average selling prices of products may decrease significantly and rapidly, especially for mobile handset products; dependence on a limited number of products and customers; risks associated with shifting market demand from GSM/GPRS to EDGE and WCDMA; difficulties developing new products that achieve market acceptance; risks that Silicon Laboratories may not be able to manage strains associated with its growth; dependence on key personnel; difficulties managing our manufacturers and subcontractors; difficulties managing international activities; credit risks associated with our accounts receivable; geographic concentration of manufacturers, assemblers, test service providers and customers in the Pacific Rim that subjects Silicon Laboratories’ business and results of operations to risks of natural disasters, epidemics, war and political unrest; product development risks; inventory-related risks; intellectual property litigation risks; risks associated with acquisitions; the competitive and cyclical nature of the semiconductor industry and other factors that are detailed in Silicon Laboratories’ filings with the SEC. Silicon Laboratories disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

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

CONTACT: Silicon Laboratories Inc., Shannon Pleasant, 512/464-9254 investor.relations@silabs.com