-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 BjP+FUnCDnh3U5kpZaMp64tsiY6xx8idO2eAKlehvx/OzYSjsK0uWRbq2XOUGSu+
 iWsHMDhpndTDzGHJyuI+EA==

<SEC-DOCUMENT>0000922423-05-000852.txt : 20050516
<SEC-HEADER>0000922423-05-000852.hdr.sgml : 20050516
<ACCEPTANCE-DATETIME>20050516163717
ACCESSION NUMBER:		0000922423-05-000852
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050513
FILED AS OF DATE:		20050516
DATE AS OF CHANGE:		20050516

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SILICONIX INC
		CENTRAL INDEX KEY:			0000090283
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				941527868
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2201 LAURELWOOD RD
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95056
		BUSINESS PHONE:		4089888000

	MAIL ADDRESS:	
		STREET 1:		2201 LAURELWOOD RD
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95056

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VISHAY INTERTECHNOLOGY INC
		CENTRAL INDEX KEY:			0000103730
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC COMPONENTS & ACCESSORIES [3670]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-03698
		FILM NUMBER:		05835044

	BUSINESS ADDRESS:	
		STREET 1:		63 LINCOLN HWY
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355
		BUSINESS PHONE:		6106441300

	MAIL ADDRESS:	
		STREET 1:		63 LINCOLN HIGHWAY
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>kl00544_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-05-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000090283</issuerCik>
        <issuerName>SILICONIX INC</issuerName>
        <issuerTradingSymbol>SILI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000103730</rptOwnerCik>
            <rptOwnerName>VISHAY INTERTECHNOLOGY INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>63 LINCOLN HWY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MALVERN</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19355</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-05-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4510363</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28540363</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-05-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1338677</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29879040</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person acquired 4,510,363 shares of the issuer in exchange for 13,869,000 shares of the reporting person at an
 exchange ratio of 3.075 shares of the reporting person for each share of the issuer.</footnote>
        <footnote id="F2">Held by Vishay TEMIC Semiconductor Acquisition Holdings Corp., which is a wholly owned subsidiary of Vishay Intertechnology,
 Inc.</footnote>
        <footnote id="F3">1,338,677 shares were acquired on May 16, 2005 by a short-form merger of Vishay Siliconix Acquisition, Inc., a Delaware
 corporation and indirectly held subsidiary of the reporting person, into the issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Richard N. Grubb, Executive V.P., Treasurer, and C.F.O.</signatureName>
        <signatureDate>2005-05-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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