Ruling Issued in SigmaTel International Trade Commission Case; SigmaTel Patents Upheld; Judge Recommends Exclusion Order

AUSTIN, Texas, Mar 21, 2006 -- SigmaTel, Inc. (NASDAQ:SGTL), a leader in mixed-signal multimedia semiconductors, today announced that an International Trade Commission (ITC) Administrative Law Judge determined that Actions Semiconductor Co., Ltd. infringed two SigmaTel patents and recommended the full ITC issue an exclusion order.

The Honorable Paul J. Luckern, the Administrative Law Judge presiding over the hearing, determined that the two patents asserted by SigmaTel at the final ITC hearing were valid and infringed. The judge also recommended that an exclusion order be issued which prevents the importation of infringing Actions chips and certain MP3 players which contain these chips. During the case, Actions had contended that it did not infringe SigmaTel's patents and that they were invalid.

"SigmaTel is ecstatic about the ITC's ruling in our case against Actions Semiconductor," said Ron Edgerton, chairman and CEO of SigmaTel. "We are proud of our patent portfolio and, with the addition of the original Moon-Hwang MP3 patents, are confident that we will have an even stronger case against IP infringement worldwide."

"With additional SigmaTel patents issuing on a regular basis, we believe it is virtually impossible for our competitors to design around SigmaTel patents and still be successful in the marketplace," Edgerton added. "We intend to protect our customers' investments in SigmaTel-based products and feel obligated to seek the ultimate legal protection achievable based on our US, European and Asian patents which apply to semiconductor competitors, player manufacturer and/or retailers. This ruling gives SigmaTel a significant legal victory and shows that SigmaTel's stated IP goals were achieved."

Specifically, the judge concluded that SigmaTel's 6,633,187 and 6,366,522 patents were valid and infringed. The ruling also included a recommendation that the ITC issue an order barring any MP3 players based on infringing Actions chips which contain two gigabytes or less of flash memory from being imported into the United States. The judge's determination and recommendation will now be reviewed by the full ITC. At this time, the ITC has only released a summary portion of the judge's determination. A public version of the full determination will be made available on SigmaTel's web site (http://www.sigmatel.com) as soon as it is released by the ITC.

SigmaTel's continued success is based in large part on protecting its intellectual property and innovating new technologies. SigmaTel protects its innovations by filing numerous patent applications and has added intellectual property via recent acquisitions, complementing its internally developed intellectual property holdings. SigmaTel has 55 issued patents and another 148 pending applications in the US Patent office. The company also has 17 patents in the European Union and 11 patents in the Asia Pacific region. Please visit http://www.sigmatel.com/about/patentedtech.asp, for specific patent information.

For more information about SigmaTel, please visit www.sigmatel.com.

About SigmaTel:

SigmaTel, Inc., a fabless semiconductor company headquartered in Austin, Texas, designs, develops, and markets proprietary, analog intensive, mixed-signal ICs for a variety of digital multimedia products in the consumer electronics and computing markets, including portable compressed audio players, such as MP3 players, notebook and desktop PCs, digital video cameras, multi-function peripheral products, digital televisions, and set-top boxes. SigmaTel provides complete, system-level solutions that include highly-integrated ICs, customizable firmware and software, software development tools, reference designs, and applications support. The Company's focus is on providing system-level solutions that enable customers to rapidly introduce and offer electronic products that are small, light-weight, power-efficient, reliable, and cost-effective. SigmaTel is ISO 9001:2000 certified and is committed to providing customers with high performance, quality products along with superior customer service.