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Exhibit 10(aaaa)

INTERNATIONAL RECTIFIER CORPORATION
2000 INCENTIVE PLAN
(Amended and Restated as of November 22, 2004)
NON-EMPLOYEE DIRECTOR NONQUALIFIED STOCK OPTION AGREEMENT

        THIS OPTION AGREEMENT is between INTERNATIONAL RECTIFIER CORPORATION, a
Delaware corporation (the "Company"), and (the "Optionee"). Pursuant to the
International Rectifier Corporation 2000 Incentive Plan (Amended and Restated as
of November 22, 2004) (the "Plan"), the Company has granted a nonqualified stock
option to purchase authorized but unissued or treasury shares of Common Stock,
$1.00 par value, of the Company as described below on the terms and conditions
attached hereto and in the Plan:

 
   
   
   
    Grant Date:   August 6, 2008                          Number of Shares:  
20,000(1)                          Exercise Price per Share:   $18.55(1)    
                     Vesting Schedule:   331/3% per year on each of the first
three anniversaries of Grant Date(1,2)                          Expiration Date:
  August 6, 2013(2)                       

(1)Subject to adjustment under Section 5.2 of the Plan.

(2)Subject to accelerated vesting and/or early termination as provided in
Section 2.5 or 5.2 of the Plan and Section 4 of the attached Terms and
Conditions, if the Optionee ceases to serve as a Non-Employee Director of the
Company or in certain other circumstances set forth in the Plan or this
Agreement. See the Terms and Conditions and the Plan for other exceptions and
additional details regarding the Option.

INTERNATIONAL RECTIFIER CORPORATION
(a Delaware Corporation)   OPTIONEE
By:
 
  
  

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(signature)
 
 
 
 
  

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Address           

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City, State, Zip Code

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TERMS AND CONDITIONS

        1.    Exercisability of Option.    Subject to earlier termination of the
Option as provided in this Agreement or the Plan and changes and adjustments
contemplated by the Plan, the Option shall vest and become exercisable in
installments of 331/3% of the aggregate number of shares set forth on the facing
page (subject to adjustment) on each of the 1st, 2nd, and 3rd anniversaries of
the Grant Date. The Option may be exercised only to the extent the Option is
exercisable.

•Cumulative Exercisability.  To the extent the Optionee does not in any year
purchase all the shares that the Optionee may then exercise, the Optionee has
the right cumulatively thereafter to purchase any shares not so purchased until
the Option terminates or expires.

•No Fractional Shares.  Fractional share interests shall be disregarded, but may
be cumulated.

•Minimum Exercise.  No fewer than 100 shares may be purchased at any one time,
unless the number purchased is the total number at the time exercisable under
the Option.

        2.    Method of Exercise of Option.    To the extent exercisable, the
Option may be exercised by the delivery to the Company of a written notice
stating the number of shares to be purchased pursuant to the Option and
accompanied by payment made in cash or by check payable to the order of the
Company in the full amount of the purchase price of the shares and any amounts
required to satisfy applicable withholding taxes. Other payment methods may be
permitted only if expressly authorized by the Administrator with respect to this
Option or all options under the Plan, consistent with Section 2.2.2 of the Plan.

        3.    Continuance of Service as a Non-Employee Director Required.    The
vesting schedule generally requires continued service through each applicable
vesting date as a condition to the vesting of the applicable installment and
rights and benefits under this Agreement. Partial service, even if substantial,
during any vesting period will not entitle the Optionee to any proportionate
vesting or avoid or mitigate a termination of rights and benefits upon or
following a termination of service, except as expressly provided in Section 4
below or under the Plan.

        4.    Effect of Termination of Service as a Non-Employee Director.    If
the Optionee's service as a Non-Employee Director of the Company terminates, the
Option and all other rights and benefits under this Agreement terminate, except
that the vesting of the Option may be accelerated and the Optionee may at any
time within the following applicable period after termination exercise the
Option to the extent set forth below, with respect to the applicable reason for
the termination of service.

•Resignation or Retirement.  If an Optionee's service as a Non-Employee Director
of the Company terminates after five consecutive years of service on the Board
as a result of his or her voluntary resignation or a decision not to stand for
re-election, the vesting of any Option held for at least six months will
immediately accelerate so that it is fully exercisable, but it will remain
exercisable only until the earlier of (a) three years from the date of
termination of services as a Non-Employee Director or (b) the expiration of the
term of the Option.

•Death or Total Disability.  If an Optionee's service as a Non-Employee Director
of the Company terminates as a result of his or her death or Total Disability,
the vesting of any Option held for at least six months will immediately
accelerate so that it is fully exercisable but, it will remain exercisable only
until the earlier of (a) three years from the date of death or Total Disability
or (b) the expiration of the term of the Option.

•Other Termination.  If an Optionee's service as a Non-Employee Director of the
Company terminates for any reason other than his or her resignation or decision
not to stand for re-election after five consecutive years of service on the
Board, or death or Total Disability, any Option held for at least six months
which is not then exercisable shall terminate and any portion of such Option
which is then exercisable will remain exercisable only until the earlier of

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(a) three months from the date of such termination or (b) the expiration of the
term of the Option.

        Subject to Section 5 below, the terms and conditions of the Plan and
changes and adjustments contemplated by the Plan, the vesting of an Option
granted less than six months prior to the applicable termination event (a
"Short-Term Option") will not automatically occur but the Board in its sole
discretion may accelerate the vesting of up to 20% of the Option as of the time
of the termination event, in which case the Option will become exercisable six
months after the Grant Date and the Option will remain exercisable until the
expiration of the applicable exercise period set forth above in this Section 4
as if the Option had been held six months at the time of termination of service.

        5.    Possible Acceleration and Termination of Awards Upon Change in
Control; Adjustments.    

        Without limiting the generality of Subsection 5.2 of the Plan or the
authority of the Administrator under the Plan, upon the occurrence of (or, as
the circumstances may require, immediately prior to) a Change in Control Event,
the Option will become immediately exercisable if it was granted six months or
more prior to the date of the Change in Control Event, unless prior to the
Change in Control Event the Board determines that benefits under all Options
granted pursuant to the Plan will not accelerate upon occurrence of the Change
in Control Event, or determines that only certain or limited benefits under all
Options granted pursuant to the Plan will be accelerated and the extent to which
they will be accelerated, and/or establishes a different time in respect of such
Change in Control Event for such acceleration. Any Short-Term Option may, in the
discretion of the Board, subject to earlier termination under other provisions
hereof, terminate on such date or continue to vest with continued service and
shall become exercisable or alternately, shall be settled in accordance with the
provisions of this Agreement and the Plan.

        6.    Notices.    Any notice to be given under the terms of this
Agreement shall be in writing and addressed to the Company at its principal
office, to the attention of the Corporate Secretary and to the Optionee at the
address given beneath the Optionee's signature, or at such other address as
either party may hereafter designate in writing to the other.

        7.    Optionee not a Stockholder.    Neither the Optionee nor any other
person entitled to exercise the Option shall have any of the rights or
privileges of a stockholder of the Company as to any shares of Common Stock not
actually issued and delivered to Optionee prior to delivery of the exercise
price and satisfaction of all other conditions precedent to the due exercise of
the Option and delivery of shares.

        8.    Effect of Award Agreement.    This Agreement shall be binding upon
and inure to the benefit of any successor or successors of the Company except to
the extent the Committee or the Board determines otherwise, consistent with the
terms of the Plan.

        9.    Choice of Law.    The construction, interpretation, performance
and enforcement of the Option and this Agreement shall be governed by the laws
of the State of California.

        10.    Defined Terms.    Capitalized terms used and not otherwise
defined herein shall have the meaning assigned to such terms in the Plan.

        11.    Plan.    The Option and all rights of Optionee thereunder are
subject to, and the Optionee agrees to be bound by, all of the terms and
conditions of the provisions of the Plan, including but not limited to
Section 5.2 (Adjustments; Acceleration) and Section 5.10 (Governing
Law/Construction/Severability). Optionee acknowledges receipt of a copy of the
Plan, which is made a part hereof by this reference. Unless otherwise expressly
provided in other Sections of this Agreement, provisions of the Plan that confer
discretionary authority on the Committee or the Board do not (and shall not be
deemed to) create any additional rights in the Optionee not expressly set forth
above.

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QuickLinks

Exhibit 10(aaaa)

INTERNATIONAL RECTIFIER CORPORATION 2000 INCENTIVE PLAN (Amended and Restated as
of November 22, 2004) NON-EMPLOYEE DIRECTOR NONQUALIFIED STOCK OPTION AGREEMENT
TERMS AND CONDITIONS