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                                                                   EXHIBIT 10.23

     CONFIDENTIAL MATERIALS OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
     EXCHANGE COMMISSION. THE LOCATIONS OF THE OMITTED MATERIALS ARE INDICATED
     BY THE FOLLOWING NOTATION: [***].

                                   Agreement

Sharp Corporation, with its head office located at 22-22 Nagaike-cho, Abeno-ku,
Osaka-shi, Osaka-fu, Japan (hereinafter "Sharp");

Sanken Electric Co., Ltd., with its head office located at 6-3, Kitano 3-chome,
Niiza-shi, Saitama-ken, Japan (hereinafter "Sanken"); and

Allegro MicroSystems, Inc., with its head office located at 115 Northeast
Cutoff, Worcester, Massachusetts 01606, U.S.A. (hereinafter "Allegro") have
concluded this Agreement as follows, as of December 28, 2006.

                                   WITNESSETH

Sharp is the right holder of the Japan registered trademark No. 2155108
"ALLEGRO" (hereinafter, the "Trademark").

Sharp and Sanken have entered into an agreement dated October 1, 1991, and a
memorandum dated October 31, 2001 on Sanken's undertaking of a license for the
use of the Trademark.

Sanken and Allegro desire to obtain the right to use the Trademark on
semiconductors (hereinafter, the "Products") within Japan.

In addition, Allegro desires to legalize the Japanese registered trademark
application No. 2004-83807 "Allegro MicroSystems Inc." (hereinafter, the
"Pending Trademark").

Sharp agrees to grant the right to use the Trademark and the Pending Trademark
on the Products within Japan to Sanken and Allegro.

Accordingly, each of the parties hereby agrees as follows.

Article 1. (Definitions)

     1.   "Trademark" means the following

          Japan registered trademark No. 2155108 "ALLEGRO"

     2.   "Pending Trademark" means the following

          Japanese registered trademark application No. 2004-83807 "Allegro
          MicroSystems Inc."

     3.   "Products" means "semiconductors".

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Article 2. (License)

     1.  Sharp shall grant to Sanken and Allegro an ordinary use license with
         regard to the Products out of the specified products of the Trademark,
         within Japan.

     2.  As a condition of the receipt of the license to the Trademark based on
         the above Paragraph, Allegro shall consent to the changing of the
         applicants name for the Pending Trademark applied for by Allegro to
         Sharp; provided however, that Allegro shall bear the processing costs
         with regard to the interim procedures and registration fees until the
         name change and legalization, and Sharp shall cooperate with such
         procedures.

     3.  Sharp shall not make any assertion of its rights based on the
         Trademark with regard to Sanken and Allegro's use of the Pending
         Trademark on the Products.

     4.  When the Pending Trademark with the applicant name changed to Sharp
         has become legalized based on Paragraph 2 of this Article, Sharp shall
         grant an ordinary use license to Sanken and Allegro for the use of the
         Pending Trademark on the Products, within Japan.

     5.  Sanken and Allegro may, at their own expense, register the
         establishment of the licenses in Paragraph 1 and Paragraph 4, and Sharp
         shall cooperate with the same.

     6.  Sharp agrees that [***].

     7.  Sharp agrees that after the Pending Trademark with the applicant name
         changed to Sharp has become legalized based on Paragraph 2 of this
         Article, [***].

Article 3. (Consideration)

     1.  As consideration for this Agreement, Sanken shall pay a lump sum of
         [***] after conclusion of this Agreement.

     2.  Sharp shall not return the consideration paid by Sanken for any
         reason.

     3.  Conditional upon the payment of the consideration in Paragraph 1 of
         this Article, Sharp shall not assert any rights with regard to Sanken
         or Allegro's use of the Pending Trademark on the Products.

Article 4. (Provision of Documents)

If Sanken or Allegro is requested by Sharp, they agree to send to Sharp
documents such as catalogues, etc. that show their use of the Trademark or the
Pending Trademark in accordance with Article 2.

Article 5. (No Warranty)

     1.  Sharp shall not bear any obligation to Sanken or Allegro, nor does it
         make any warranty, to maintain the trademark rights or eliminate
         infringements by third parties with regard to the Trademark (including
         the "Pending Trademark" where it has been legalized based on Article 2
         Paragraph 4. The same to apply in the following Paragraphs).

     2.  If the Trademark is infringed by a third party, and Sharp is requested
         for cooperation by Sanken or Allegro, if Sharp decides that some kind
         of action is necessary and desirable, it may take necessary actions, at
         the cost of Sanken or Allegro, within the


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          scope desired by Sanken or Allegro, and based on agreement between
          Sharp, Sanken and Allegro.

     3.   If Sanken or Allegro makes an appeal for cancellation due to lack of
          use, or other application, demand or claim to the disadvantage of
          Sharp against the Trademark, the Pending Trademark or any similar
          trademark, Sharp may terminate this Agreement.

Article 6. (Assignment)

[***]

Article 7. (Term)

     1.   The term of this Agreement shall be for 10 years from October 1, 2006;
          provided however, that the agreement term may be extended on
          conditions to be separately discussed if, by 6 months prior to the
          expiry of the term, Sanken proposes to extend the agreement.

     2.   This Agreement shall replace the Agreement dated October 1, 1991 and
          the Memorandum dated October 31, 2001 between Sharp and Sanken.

Article 8. (Consultation)

If any doubts arise regarding matters for which there is no provision in this
Agreement or regarding the interpretation hereof, Sharp, Sanken and Allegro
shall consult and resolve them in good faith.

Article 9. (Dispute Resolution)

Where a dispute that has arisen with regard to this Agreement cannot be resolved
in accordance with Article 8, it shall be resolved by a court. In this case, the
Osaka District Court shall be the court with jurisdiction in the first instance.

Article 10. (Governing Law)

The governing law of this Agreement shall be Japanese law.


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In witness whereof, this Agreement has been prepared in three parts, and Sharp,
Sanken and Allegro shall each retain one part.

December 28, 2006

Sharp:   22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka-fu
         Sharp Corporation
         Intellectual Property Headquarters
         General Manager
         Shigeo Terajima
         [seal affixed]

Sanken:  6-3, Kitano 3-chome, Niiza-shi, Saitama-ken
         Sanken Electric Co., Ltd.
         Director, Executive Vice President
         General Manager of Engineering Headquarters
         Hirohito Sekine
         [seal affixed]

Allegro: 115 Northeast Cutoff, Worcester, Massachusetts 01606
         Allegro MicroSystems, Inc.
         Vice President and General Counsel
         Fred Windover

         /s/ Fred Windover



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