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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Bahpen3e7g2aoU6TFdiwot45Evzna2hlyLUygezoA5zYZEjW4Pnrs9i7HWhO0inz
 x2CdE/uRhgaNVMhmc1Lapg==

<SEC-DOCUMENT>0001246948-03-000002.txt : 20030725
<SEC-HEADER>0001246948-03-000002.hdr.sgml : 20030725
<ACCEPTANCE-DATETIME>20030725114826
ACCESSION NUMBER:		0001246948-03-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030724
FILED AS OF DATE:		20030725

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MCGOVERN JOHN W
		CENTRAL INDEX KEY:			0001246948

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-29823
		FILM NUMBER:		03802548

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

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
</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>2003-07-24</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001246948</rptOwnerCik>
            <rptOwnerName>MCGOVERN JOHN W</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>Vice President &amp; CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock, $0.0001 par value</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-24</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>20000</value>
            </transactionShares>
            <transactionValue>
                <value>37.965</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>50000</value>
                <footnoteId id="F1"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>JMAP Investments LTD.</value>
                <footnoteId id="F2"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">In addition to the 50,000 shares that Mr. McGovern claims indirect beneficial ownership of through JMAP Investments LTD., Mr. McGovern claims direct ownership of 76,200 shares.</footnote>
        <footnote id="F2">JMAP Investments Ltd. is a limited partnership of which the reporting person and his wife are the sole general partners and of which the reporting person, his wife and the McGovern Family Trust are the sole limited partners.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>John W. McGovern</signatureName>
        <signatureDate>2003-07-25</signatureDate>
    </ownerSignature>

</ownershipDocument>

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