-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 DeIZ3QIudaL8ZUllQpYSHedCnf2OoY3FWvo9vkwypHQ4J1QrUq80tevYf0kHJGh3
 /pPrqkrmaMQONCQMFQL+9g==

<SEC-DOCUMENT>0001197845-03-000008.txt : 20030506
<SEC-HEADER>0001197845-03-000008.hdr.sgml : 20030506
<ACCEPTANCE-DATETIME>20030506155946
ACCESSION NUMBER:		0001197845-03-000008
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030502
FILED AS OF DATE:		20030506

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SILICON LABORATORIES INC
		CENTRAL INDEX KEY:			0001038074
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				742793174
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4635 BOSTON LN
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78735

	MAIL ADDRESS:	
		STREET 1:		4635 BOSTON LANE
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78735

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ARTUSI DANIEL A
		CENTRAL INDEX KEY:			0001197847

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-29823
		FILM NUMBER:		03684361

	BUSINESS ADDRESS:	
		STREET 1:		4635 BOSTON LANE
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78735
		BUSINESS PHONE:		5124168500
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-05-02</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001038074</issuerCik>
        <issuerName>SILICON LABORATORIES INC</issuerName>
        <issuerTradingSymbol>SLAB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001197847</rptOwnerCik>
            <rptOwnerName>ARTUSI DANIEL A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock, $0.0001 par value</value>
        </securityTitle>
        <transactionDate>
            <value>2003-05-02</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>M</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>25000</value>
            </transactionShares>
            <transactionValue>
                <value>20.24</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>154172</value>
                <footnoteId id="F1"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock, $0.0001 par value</value>
        </securityTitle>
        <transactionDate>
            <value>2003-05-02</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>25000</value>
            </transactionShares>
            <transactionValue>
                <value>30.0023</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>129172</value>
                <footnoteId id="F1"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Non-Qualified Stock Option (right to buy)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>20.24</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-05-02</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>M</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>25000</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
                <footnoteId id="F3"/>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2002-08-27</value>
            <footnoteId id="F2"/>
        </exerciseDate>
        <expirationDate>
            <value>2011-08-27</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock, $0.0001 par value</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>25000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>356500</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">Includes 200 shares acquired under the Silicon Laboratories Inc. employee stock purchase plan on October 31, 2002 and 200 shares acquired from the Silicon Laboratories Inc. employee stock purchase plan on April 30, 2003.</footnote>
        <footnote id="F2">Option first became exercisable on August 27, 2002.  Option vests and becomes exercisable over a 60-month period, with respect to (i) twenty percent (20%) of the option shares vest and become exercisable upon optionee's completion of one year of service measured from August 27, 2001 and (ii) the balance of the option shares vest and become exercisable in a series of forty-eight (48) successive monthly installments over the forty-eight (48) month period measured from the first year anniversary of August 27, 2001.</footnote>
        <footnote id="F3">Not applicable per instruction 4(c)(iii).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Daniel A. Artusi</signatureName>
        <signatureDate>2003-05-05</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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