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Exhibit 5.1

[Dorsey & Whitney LLP Letterhead]

ADC Telecommunications, Inc.
13625 Technology Drive
Eden Prairie, Minnesota 55344-2252
(952) 938-8080

Re:

Registration Statement on Form S-3

        Ladies and Gentlemen:

        We are acting as counsel for ADC Telecommunications, Inc., a Minnesota corporation (the "Company") in connection with the registration under the Securities Act of 1933, as amended, of $200,000,000 aggregate principal amount of 1.00% Convertible Subordinated Notes Due 2008 and $200,000,000 aggregate principal amount of Floating Rate Convertible Subordinated Notes Due 2013 (the "Notes") pursuant to the Indenture dated as of June 4, 2003, between the Company and U.S. Bank National Association, as Trustee (the "Indenture"), and the number of shares of Common Stock, par value $0.20 per share, of the Company, as may be required for issuance upon conversion of the Notes (the "Conversion Shares"). The Notes and the Conversion Shares are to be offered and sold by certain securityholders of the Company (the "Selling Securityholders"). In this regard we have participated in the preparation of a Registration Statement on Form S-3 relating to the Notes and the Conversion Shares (such Registration Statement, as it may be amended from time to time, is herein referred to as the "Registration Statement").

        We have examined such documents and have reviewed such questions of law as we have considered necessary and appropriate for the purposes of our opinion set forth below. In rendering our opinion, we have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures and the conformity to authentic originals of all documents submitted to us as copies. We have also assumed the legal capacity for all purposes relevant hereto of all natural persons and, with respect to all parties to agreements or instruments relevant hereto other than the Company, that such parties had the requisite power and authority (corporate or otherwise) to execute, deliver and perform such agreements or instruments, that such agreements or instruments have been duly authorized by all requisite action (corporate or otherwise), executed and delivered by such parties and that such agreements or instruments are the valid, binding and enforceable obligations of such parties. As to questions of fact material to our opinion, we have relied upon certificates of officers of the Company and of public officials.

        We are of the opinion that the Notes have been duly authorized, have been duly completed, executed, authenticated and delivered in accordance with the Indenture, and are the valid and binding obligations of the Company entitled to the benefits of the Indenture, subject to the following:

        (a)   We express no opinion as to (i) the effect of any bankruptcy, insolvency, reorganization, arrangement, fraudulent conveyance, moratorium or other similar laws relating to or affecting the rights of creditors generally, including, without limitation, laws relating to fraudulent transfers or conveyances and preferences, (ii) rights to indemnification and contribution contained in the Notes, the Indenture and the Registration Rights Agreement dated as of June 4, 2003 between the Company and Banc of America Securities LLC, Credit Suisse First Boston LLC and Merrill Lynch, Pierce, Fenner & Smith Incorporated, which may be limited by applicable law or equitable principles, or (iii) the effect of general principles of equity, including without limitation, concepts of materiality, reasonableness, good faith and fair dealing, and the possible unavailability of specific performance, injunctive relief or other equitable relief, and limitations on rights of acceleration regardless of whether considered in a proceeding in equity or at law.

        (b)   To the extent that the obligations of the Company under the Indenture may be dependent upon such matters, we assume for purposes of this opinion that the Trustee under the Indenture has been duly organized, is validly existing and is in good standing under the laws of its jurisdiction of organization; that the Trustee is duly qualified to engage in the activities contemplated by the Indenture; that the Indenture has been duly authorized, executed and delivered by the Trustee and constitutes a legally valid, binding and enforceable obligation of the Trustee enforceable against the Trustee in accordance with its terms; that the Trustee is in compliance, generally and with respect to acting as trustee under the Indenture, with all applicable laws and regulations; and that the Trustee has the requisite organizational and legal power and authority to perform its obligations under the Indenture.

        (c)   Minnesota Statutes §290.371, Subd. 4, provides that any corporation required to file a Notice of Business Activities Report does not have a cause of action upon which it may bring suit under Minnesota law unless the corporation has filed a Notice of Business Activities Report and provides that the use of the courts of the State of Minnesota for all contracts executed and all causes of action that arose before the end of any period for which a corporation failed to file a required report is precluded. Insofar as our opinion may relate to the valid, binding and enforceable character of any agreement under Minnesota law or in Minnesota court, we have assumed that any party seeking to enforce such agreement has at all times been, and will continue at all times to be, exempt from the requirement of filing a Notice of Business Activities Report or, if not exempt, has duly filed, and will continue to duly file, all Notice of Business Activities Reports.

        We are of the further opinion that the Conversion Shares have been duly authorized and, when issued by the Company upon conversion of the Notes in accordance with the Indenture, will be legally issued, fully paid and nonassessable.

        Our opinions expressed above are limited to the laws of the State of Minnesota.

        We hereby consent to the filing of this opinion as an exhibit to the Registration Statement, and to the reference to our firm under the heading "Legal Matters" in the Prospectus constituting part of the Registration Statement.

Dated: August 26, 2003

Very truly yours,
/s/ Dorsey & Whitney LLP

JLS/DLS

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Exhibit 5.1