<PAGE>
PROSPECTUS SUPPLEMENT NO. 3 FILED PURSUANT TO RULE 424(b)(3)
(TO PROSPECTUS DATED NOVEMBER 24, 2000) REGISTRATION NO. 333-48030
[INTERNATIONAL RECTIFIER LOGO]
INTERNATIONAL RECTIFIER CORPORATION
$550,000,000 4 1/4% CONVERTIBLE SUBORDINATED NOTES DUE 2007
AND
7,438,967 SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION OF THE NOTES
This prospectus supplement relates to the resale by holders of our 4 1/4%
Convertible Subordinated Notes Due 2007 and shares of common stock issuable upon
the conversion of the notes. This prospectus supplement may only be delivered or
used in connection with our prospectus dated November 24, 2000. Our common stock
is listed on The New York Stock Exchange and the Pacific Exchange under the
symbol "IRF."
NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE
ADEQUACY OR ACCURACY OF THIS PROSPECTUS SUPPLEMENT OR THE RELATED PROSPECTUS.
ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
PROSPECTUS SUPPLEMENT DATED DECEMBER 22, 2000
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The information appearing in the following table supplements or supersedes
in part the information in the table under the heading "Selling Holders" in our
prospectus and was provided by or on behalf of the selling holders.
<TABLE>
<CAPTION>
COMMON
STOCK
BENEFICIALLY
OWNED AFTER
PRINCIPAL AMOUNT OF COMMON STOCK OFFERING
NOTES BENEFICIALLY BENEFICIALLY OWNED COMMON STOCK -------------------
NAME AND ADDRESS OWNED AND OFFERED BEFORE OFFERING OFFERED(1) AMOUNT %
---------------- ------------------- ------------------ -------------- -------- --------
<S> <C> <C> <C> <C> <C>
KBC Financial Products USA Inc............. $ 1,200,000 0 16,230 0 *
120 West 45th Street
Tower 45, 25th Floor
New York, NY 10036
Salomon Smith Barney Inc................... $ 11,750,000 0 158,923 0 *
390 Greenwich St.
3rd Floor--Convertibles
New York, NY 10013
Any other holder of notes or future
transferee, pledgee, donee or successor
of any
holder (2)(3)............................ $ 85,407,000 0 1,155,164 0 *
</TABLE>
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* Less than 1%
(1) Assumes conversion of all the holder's notes at a conversion price of
$73.935 per share of common stock and resale of all shares of common stock
offered hereby.
(2) Information about other selling security holders will be set forth in
prospectus supplements, if required.
(3) Assumes that any other holders of notes, or any future transferees,
pledgees, donees or successors of or from any such other holders of notes,
do not beneficially own any common stock other than the common stock
issuable upon conversion of the notes at the initial conversion rate.
Information concerning the selling holders may change from time to time and
any changed information will be set forth in supplements or amendments to the
prospectus if necessary. In addition, the per share conversion price, and
therefore the number of shares of common stock issuable upon conversion of the
notes, is subject to adjustment. As a result, the aggregate principal amount of
the notes and the number of shares of common stock into which the notes are
convertible may increase or decrease.
S-2
