<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-08-22</periodOfReport>
    <issuer>
        <issuerCik>0000827054</issuerCik>
        <issuerName>MICROCHIP TECHNOLOGY INC</issuerName>
        <issuerTradingSymbol>MCHP</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181928</rptOwnerCik>
            <rptOwnerName>SANGHI STEVE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MICROCHIP TECHNOLOGY INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>2355 WEST CHANDLER BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>CHANDLER</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85224-6199</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>President, CEO, Chairman</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-08-22</value></transactionDate><deemedExecutionDate><value>2003-08-22</value></deemedExecutionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>G</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>270</value></transactionShares><transactionPricePerShare><value>27.25</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2750696</value><footnoteId id="F1"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>Held Directly and Indirectly, In Trust</value><footnoteId id="F1"/></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Of the 2,750,696 shares held, 24,190 are held Directly and 2,726,506 are held Indirectly, in Trust.</footnote></footnotes><remarks/><ownerSignature><signatureName>Steve Sanghi</signatureName><signatureDate>2003-08-25</signatureDate></ownerSignature></ownershipDocument>

