<PAGE>   1



     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 13, 1999

                                                    REGISTRATION NO. 333-_______

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                             ----------------------

                                    FORM S-8
                  REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                              UNITRODE CORPORATION
                              --------------------
             (Exact Name of Registrant as Specified in its Charter)
<TABLE>
<S>                                                        <C>
     MARYLAND                                                 04-2271186
---------------------------------                          ------------------
(State or other jurisdiction                               (I.R.S. Employer
of incorporation or organization)                          Identification No.)
</TABLE>

             7 CONTINENTAL BOULEVARD, MERRIMACK, NEW HAMPSHIRE 03054
             -------------------------------------------------------
               (Address of principal executive offices) (Zip Code)

                              UNITRODE CORPORATION
                           1999 EQUITY INCENTIVE PLAN
                              UNITRODE CORPORATION
                          EMPLOYEE STOCK PURCHASE PLAN
                          ----------------------------
                             (Full Titles of Plans)

<TABLE>
<S>                                                      <C>
          ALLAN R. CAMPBELL, ESQUIRE                                    Copy to:
  SENIOR VICE PRESIDENT, GENERAL COUNSEL AND                  JAMES J. HANKS, JR., ESQUIRE
                  SECRETARY                              BALLARD SPAHR ANDREWS & INGERSOLL, LLP
             UNITRODE CORPORATION                         300 EAST LOMBARD STREET, SUITE 1900
           7 CONTINENTAL BOULEVARD                             BALTIMORE, MARYLAND 21202
        MERRIMACK, NEW HAMPSHIRE 03054                               (410) 528-5600
                (603) 424-2410
                --------------
(Name, address and telephone number, including
       area code, of agent for service)

</TABLE>

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Title of                                                     Proposed Maximum     Proposed Maximum
Securities to       Amount to be                             Offering Price       Aggregate            Amount of
be Registered       Registered                               per Share (3)        Offering Price       Registration Fee
------------------------------------------------------------------------------------------------------------------------
<S>                 <C>                                      <C>                  <C>                  <C>
Common Stock, $.01
par value per share    3,085,368(2)                           $28.22               $87,069,084.96        $24,205.21
------------------------------------------------------------------------------------------------------------------------
Common Stock, $.01
par value per share     200,000(4)                            $28.22               $ 5,644,000.00        $ 1,569.03
------------------------------------------------------------------------------------------------------------------------
</TABLE>

(1) Pursuant to Rule 416(a) under the Securities Act of 1933, this Registration
Statement shall be deemed to cover an indeterminate number of additional shares
of Common Stock issuable in the event the number of outstanding shares of
Unitrode Corporation is increased by split-up, reclassification, stock dividend
or similar transactions.

(2) Represents the number of shares of Common Stock authorized for issuance
pursuant to the Unitrode Corporation 1999 Equity Incentive Plan.

(3) Estimated solely for the purpose of determining the registration fee
pursuant to Rule 457(c) and (h) under the Securities Act of 1933, as amended.
The proposed maximum offering price per share is based upon the average of high
and low prices for shares of Common Stock of the Registrant on the New York
Stock Exchange on June 21, 1999.

(4) Represents the number of shares of Common Stock authorized for issuance
pursuant to the Unitrode Corporation Employee Stock Purchase Plan.


<PAGE>   2

                                    PART I

             INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1.      Plan Information.

            The Registrant will send or give the documents containing the
information specified in this Item 1 to employees, officers, directors or others
as specified by Rule 428(b). In accordance with the rules and regulations of the
Securities and Exchange Commission (the "Commission") and the instructions to
Form S-8, the Registrant is not filing such documents with the Commission either
as part of this Registration Statement or as prospectuses or prospectus
supplements pursuant to Rule 424.

Item 2.     Registrant Information and Employee Plan Annual Information.

            The Registrant will send or give the documents containing the
information specified in this Item 2 to employees, officers, directors or others
as specified by Rule 428(b). In accordance with the rules and regulations of the
Commission and the instructions to Form S-8, the Registrant is not filing such
documents with the Commission either as part of this Registration Statement or
as prospectuses or prospectus supplements pursuant to Rule 424.

                                      I-1


<PAGE>   3

                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.     Incorporation of Documents by Reference.

            The following documents and information heretofore filed with the
Commission by the Registrant are incorporated herein by reference:

            (a)   The Registrant's Annual Report on Form 10-K for the fiscal
                  year ended January 31, 1999;

            (b)   The Registrant's Quarterly Report on Form 10-Q for the fiscal
                  quarter ended May 1, 1999;

            (c)   The Registrant's Current Reports on Form 8-K filed February
                  15, 1999, Form 8-K filed March 15, 1999 and Form 8-K filed
                  June 28, 1999;

            (d)   The description of the Registrant's common stock, par value
                  $.01 per share, set forth in the Registrant's Registration
                  Statement filed under the Securities Exchange Act of 1934,
                  including any amendments or reports filed for the purpose of
                  updating such description.

            All documents subsequently filed with the Commission by the
Registrant pursuant to Section 13(a), 13(c), 14 and 15(d) of the Securities
Exchange Act of 1934, as amended, prior to the filing of a post-effective
amendment which indicates that all securities offered hereunder have been sold
or which deregisters all securities then remaining unsold under this
Registration Statement shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents. Any statement contained herein or in a document incorporated or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Registration Statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such earlier statement. Any statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute part of this
Registration Statement.

Item 4.     Description of Securities.

            Not applicable.

Item 5.     Interests of Named Experts and Counsel.

            Not applicable.

                                      II-1
<PAGE>   4


Item 6.     Indemnification of Directors and Officers.

            The Maryland General Corporation Law permits a Maryland corporation
to include in its charter a provision limiting the liability of its directors
and officers to the corporation and its stockholders for money damages except
for liability resulting from (a) actual receipt of an improper benefit or profit
in money, property or services or (b) active and deliberate dishonesty
established by a final judgment as being material to the cause of action. The
charter of Unitrode Corporation, a Maryland corporation (the "Registrant"),
contains such a provision which eliminates such liability except (a) to the
extent that it is proved that the person actually received an improper benefit
or profit in money, property or services, for the amount of the benefit or
profit in money, property or services actually received, or (b) to the extent
that a judgment or other final adjudication adverse to the person is entered in
a proceeding based on a finding in the proceeding that the person's action, or
failure to act, was the result of active and deliberate dishonesty and was
material to the cause adjudicated in the proceeding.

            The Registrant's Amended and Re-stated By-Laws obligate it, to the
maximum extent permitted by Maryland law, to indemnify and to pay or reimburse
reasonable expenses in advance of final disposition of a proceeding to (a) any
individual who is a present or former director or officer or (b) any individual
who, while a director of the Registrant and at the request of the Registrant,
serves or has served another corporation, partnership, joint venture, trust,
employee benefit plan or any other enterprise as a director, officer, partner or
trustee of such corporation, partnership, joint venture, trust, employee benefit
plan or other enterprise. The Registrant's Amended and Re-stated By-Laws also
permit the Registrant to indemnify and advance expenses to any person who served
a predecessor of the Registrant in any of the capacities described above and to
any employee or agent of the Registrant or a predecessor of the Registrant.

            The Maryland General Corporation Law requires a corporation (unless
its charter provides otherwise, which the Registrant's charter does not) to
indemnify a director or officer who has been successful, on the merits or
otherwise, in the defense of any proceeding to which he is made a party by
reason of his service in that capacity. The Maryland General Corporation Law
permits a corporation to indemnify its present and former directors and
officers, among others, against judgments, penalties, fines, settlements and
reasonable expenses actually incurred by them in connection with any proceeding
to which they may be made a party by reason of their service in those or other
capacities unless it is established that (a) the act or omission of the director
or officer was material to the matter giving rise to the proceeding and (i) was
committed in bad faith or (ii) was the result of active and deliberate
dishonesty, (b) the director or officer actually received an improper personal
benefit in money, property or services or (c) in the case of any criminal
proceeding, the director or officer had reasonable cause to believe that the act
or omission was unlawful. However, under the Maryland General Corporation Law, a
Maryland corporation may not indemnify for an adverse judgment in a suit by or
in the right of the corporation or for a judgment of liability on the basis that
personal benefit was improperly received, unless in either case a court orders
indemnification and then only for expenses. In addition, the Maryland General
Corporation Law requires a corporation, as a condition to

                                      II-2
<PAGE>   5

advancing reasonable expenses, to obtain (a) a written affirmation by the
director or officer of his good faith belief that he has met the standard of
conduct necessary for indemnification by the corporation and (b) a written
undertaking by him or on his behalf to repay the amount paid or reimbursed by
the corporation if it shall ultimately be determined that the standard of
conduct was not met.

            The Registrant's officers and directors are insured against certain
liabilities under a policy maintained by the Registrant with an aggregate
coverage of $10,000,000.

Item 7.     Exemption From Registration Claimed.

            Not claimed.

Item 8.     Exhibits.

4.1         Articles of Restatement of the Charter of the Registrant and
            Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3A to the Registrant's Annual Report on Form 10K
            for the fiscal year ended January 31, 1989 and incorporated herein
            by reference.

4.2         Articles Supplementary to the Charter of the Registrant, previously
            filed as Exhibits 3(A)(1) and (6) to the Registrant's Current Report
            on Form 8-K filed May 4, 1990 and incorporated herein by reference.

4.3         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3B to the Registrant's Annual Report on Form 10-K
            for fiscal year ended January 31, 1992 and incorporated herein by
            reference.

4.4         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3D to the Registrant's Annual Report on Form 10-K
            for the fiscal year ended January 31, 1998, and incorporated herein
            by reference.

4.5         Amended and Re-stated By-Laws of the Registrant.

4.6         Rights Agreement dated as of May 2, 1990 between the Registrant and
            The First National Bank of Boston as Rights Agent, previously filed
            as Exhibit 1 to the Registrant's Registration Statement on Form 8-A
            dated May 3, 1990 and incorporated herein by reference.

4.7         First Amendment, dated as of April 30, 1993, to the Rights
            Agreement, dated as of May 2, 1990, between the Registrant and The
            First National Bank of Boston, as Rights Agent, previously filed as
            Exhibit 1 to Form 8-A/A, Amendment to Registration Statement on Form
            8-A, dated May 26, 1993 and incorporated herein by reference.

                                      II-3
<PAGE>   6


4.8         Unitrode Corporation 1999 Equity Incentive Plan, previously filed as
            Appendix A to the Registrant's Proxy Statement for its 1999 Annual
            Meeting of Stockholders on Schedule 14A, filed April 27, 1999.

4.9         Unitrode Corporation Employee Stock Purchase Plan (as amended as of
            July 6, 1999).

5.1         Opinion of Ballard Spahr Andrews & Ingersoll, LLP.

23.1        Consent of PricewaterhouseCoopers LLP.

23.2        Consent of Ernst & Young LLP.

23.3        Consent of Ballard Spahr Andrews & Ingersoll, LLP (included in
            Exhibit 5.1).

24.1        Powers of Attorney (included on page II-6 hereof).

Item 9.     Undertakings.

(a)   The undersigned Registrant hereby undertakes:

                  (1) To file, during any period in which offers or sales are
      being made, a post-effective amendment to this registration statement:

                            (i) To include any prospectus required by
            Section 10(a)(3) of the Securities Act of 1933, as amended;

                           (ii) To reflect in the prospectus any facts or events
            arising after the effective date of the registration statement (or
            the most recent post-effective amendment thereof) which,
            individually or in the aggregate, represent a fundamental change in
            the information set forth in the registration statement.
            Notwithstanding the foregoing, any increase or decrease in volume of
            securities offered (if the total dollar value of securities offered
            would not exceed that which was registered) and any deviation from
            the low or high and of the estimated maximum offering range may be
            reflected in the form of prospectus filed with the Commission
            pursuant to Rule 424(b) if, in the aggregate, the changes in volume
            and price represent no more than a 20 percent change in the maximum
            aggregate offering price set forth in the "Calculation of
            Registration Fee" table in the effective registration statement.

                          (iii) To include any material information with respect
            to the plan of distribution not previously disclosed in the
            registration statement or any material change in such information in
            the registration statement;

                                      II-4
<PAGE>   7


      provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
      if the information required to be included in a post-effective amendment
      by those paragraphs is contained in periodic reports filed with or
      furnished to the Commission by the Registrant pursuant to Section 13 or
      15(d) of the Exchange Act that are incorporated by reference in the
      registration statement.

                  (2) That, for the purpose of determining any liability under
      the Securities Act of 1933, as amended, each such post-effective amendment
      shall be deemed to be a new registration statement relating to the
      securities offered therein, and the offering of such securities at that
      time shall be deemed to be the initial bona fide offering thereof.

                  (3) To remove from registration by means of a post-effective
      amendment any of the securities being registered which remain unsold at
      the termination of the offering.

            (b) The undersigned Registrant hereby undertakes that, for purposes
of determining any liability under the Securities Act of 1933, as amended, each
filing of the Registrant's annual report pursuant to Section 13(a) or Section
15(d) of the Exchange Act (and, where applicable, each filing of an employee
benefit plan's annual report pursuant to Section 15(d) of the Exchange Act) that
is incorporated by reference in the registration statement shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

            (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933, as amended, may be permitted to directors, officers and
controlling persons of the Registrant pursuant to the foregoing provisions, or
otherwise, the Registrant has been advised that in the opinion of the Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933, as amended, and is, therefore, unenforceable. In the event that a claim
for indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act of 1933, as amended, and will be governed by the final adjudication of such
issue.

                                      II-5
<PAGE>   8


                                    SIGNATURES

            Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Merrimack, State of New Hampshire, on this 6th day of
July, 1999.

                                    Unitrode Corporation, a Maryland
                                    corporation (Registrant)

                                    By:   /s/ Robert J. Richardson
                                          ---------------------------------
                                          Robert J. Richardson,
                                          Chairman, President and Chief
                                          Executive Officer

                               POWER OF ATTORNEY

            KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Robert J. Richardson and Allan R.
Campbell, jointly and severally, his true and lawful attorneys-in-fact, each
with full power of substitution and resubstitution, for him and in his name,
place and stead, in any and all capacities, to sign any amendments and
supplements to this Registration Statement (including post-effective
amendments), and to file the same, with all exhibits thereto and other documents
in connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that each of said attorneys-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof.

            Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.


<TABLE>
<CAPTION>
      NAME                              TITLE                                                  DATE
<S>                                     <C>                                                 <C>
/s/ Robert J. Richardson                Chairman, President and Chief Executive             July 6, 1999
-------------------------------         Officer (principal executive officer) and Director
Robert J. Richardson


/s/ John L. Kokulis                     Executive Vice President and                        July 6, 1999
-------------------------------         Chief Financial Officer
John L. Kokulis                         (principal financial and accounting
                                        officer)


/s/ Robert L. Gable                     Director                                            July 6, 1999
-------------------------------
Robert L. Gable

/s/ Dietrich R. Erdmann                 Director                                            July 6, 1999
-------------------------------
Dietrich R. Erdmann

/s/ William W.R. Elder                  Director                                            July 6, 1999
-------------------------------
William W.R. Elder

/s/ Louis E. Lataif                     Director                                            July 6, 1999
-------------------------------
Louis E. Lataif

/s/ James T. Vanderslice                Director                                            July 6, 1999
-------------------------------
James T. Vanderslice
</TABLE>

                                      II-6

<PAGE>   9

                                 EXHIBIT INDEX
<TABLE>
<CAPTION>
EXHIBIT
  NO.                        DESCRIPTION OF EXHIBIT
<S>         <C>
4.1         Articles of Restatement of the Charter of the Registrant and
            Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3A to the Registrant's Annual Report on Form 10K
            for the fiscal year ended January 31, 1989 and incorporated herein
            by reference.

4.2         Articles Supplementary to the Charter of the Registrant, previously
            filed as Exhibits 3(A)(1) and (6) to the Registrant's Current Report
            on Form 8-K filed May 4, 1990 and incorporated herein by reference.

4.3         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3B to the Registrant's Annual Report on Form 10-K
            for fiscal year ended January 31, 1992 and incorporated herein by
            reference.

4.4         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3D to the Company's Annual Report on Form 10-K for
            the fiscal year ended January 31, 1998, and incorporated herein by
            reference.

4.5         Amended and Re-stated By-Laws of the Registrant.

4.6         Rights Agreement dated as of May 2, 1990 between the Registrant and
            The First National Bank of Boston as Rights Agent, previously filed
            as Exhibit 1 to the
</TABLE>

                                      II-7
<PAGE>   10

<TABLE>
<S>         <C>
            Registrant's Registration Statement on Form 8-A dated May 3, 1990
            and incorporated herein by reference.

4.7         First Amendment, dated as of April 30, 1993, to the Rights
            Agreement, dated as of May 2, 1990, between the Company and the
            First National Bank of Boston, as Rights Agent, previously filed as
            Exhibit 1 to Form 8-A/A, Amendment to Registration Statement on Form
            8-A, dated May 26, 1993 and incorporated herein by reference.

4.8         Unitrode Corporation 1999 Equity Incentive Plan (as amended as of
            July 6, 1999).

4.9         Unitrode Corporation Employee Stock Purchase Plan, previously filed
            as Appendix B to the Proxy Statement for the 1999 Annual Meeting the
            Stockholders on Schedule 14A, filed April 27, 1999.

5.1         Opinion of Ballard Spahr Andrews & Ingersoll, LLP.

23.1        Consent of PricewaterhouseCoopers LLP.

23.2        Consent of Ernst & Young LLP.

23.3        Consent of Ballard Spahr Andrews & Ingersoll, LLP (included in
            Exhibit 5.1).

24.1        Powers of Attorney (included on page II-6 hereof).
</TABLE>

                                      II-8
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 26256}]
{"company-data": {"conformed-name": "UNITRODE CORP", "cik": "0000101911", "assigned-sic": "3674", "irs-number": "042271186", "state-of-incorporation": "MD", "fiscal-year-end": "0131"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-82777", "film-number": "99663789"}, "business-address": {"street1": "7 CONTINENTAL BLVD", "city": "MERRIMACK", "state": "NH", "zip": "03054", "phone": "6034242410"}, "mail-address": {"street1": "7 CONTINENTAL BLVD", "city": "MERRIMACK", "state": "NH", "zip": "03054"}}
1

     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 13, 1999

                                                    REGISTRATION NO. 333-_______

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                             ----------------------

                                    FORM S-8
                  REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                              UNITRODE CORPORATION
                              --------------------
             (Exact Name of Registrant as Specified in its Charter)
MARYLAND                                                 04-2271186
---------------------------------                          ------------------
(State or other jurisdiction                               (I.R.S. Employer
of incorporation or organization)                          Identification No.)
7 CONTINENTAL BOULEVARD, MERRIMACK, NEW HAMPSHIRE 03054
             -------------------------------------------------------
               (Address of principal executive offices) (Zip Code)

                              UNITRODE CORPORATION
                           1999 EQUITY INCENTIVE PLAN
                              UNITRODE CORPORATION
                          EMPLOYEE STOCK PURCHASE PLAN
                          ----------------------------
                             (Full Titles of Plans)
ALLAN R. CAMPBELL, ESQUIRE                                    Copy to:
  SENIOR VICE PRESIDENT, GENERAL COUNSEL AND                  JAMES J. HANKS, JR., ESQUIRE
                  SECRETARY                              BALLARD SPAHR ANDREWS & INGERSOLL, LLP
             UNITRODE CORPORATION                         300 EAST LOMBARD STREET, SUITE 1900
           7 CONTINENTAL BOULEVARD                             BALTIMORE, MARYLAND 21202
        MERRIMACK, NEW HAMPSHIRE 03054                               (410) 528-5600
                (603) 424-2410
                --------------
(Name, address and telephone number, including
       area code, of agent for service)
CALCULATION OF REGISTRATION FEE
------------------------------------------------------------------------------------------------------------------------
Title of                                                     Proposed Maximum     Proposed Maximum
Securities to       Amount to be                             Offering Price       Aggregate            Amount of
be Registered       Registered                               per Share (3)        Offering Price       Registration Fee
------------------------------------------------------------------------------------------------------------------------
Common Stock, $.01
par value per share    3,085,368(2)                           $28.22               $87,069,084.96        $24,205.21
------------------------------------------------------------------------------------------------------------------------
Common Stock, $.01
par value per share     200,000(4)                            $28.22               $ 5,644,000.00        $ 1,569.03
------------------------------------------------------------------------------------------------------------------------
(1) Pursuant to Rule 416(a) under the Securities Act of 1933, this Registration
Statement shall be deemed to cover an indeterminate number of additional shares
of Common Stock issuable in the event the number of outstanding shares of
Unitrode Corporation is increased by split-up, reclassification, stock dividend
or similar transactions.

(2) Represents the number of shares of Common Stock authorized for issuance
pursuant to the Unitrode Corporation 1999 Equity Incentive Plan.

(3) Estimated solely for the purpose of determining the registration fee
pursuant to Rule 457(c) and (h) under the Securities Act of 1933, as amended.
The proposed maximum offering price per share is based upon the average of high
and low prices for shares of Common Stock of the Registrant on the New York
Stock Exchange on June 21, 1999.

(4) Represents the number of shares of Common Stock authorized for issuance
pursuant to the Unitrode Corporation Employee Stock Purchase Plan.
2

                                    PART I

             INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1.      Plan Information.

            The Registrant will send or give the documents containing the
information specified in this Item 1 to employees, officers, directors or others
as specified by Rule 428(b). In accordance with the rules and regulations of the
Securities and Exchange Commission (the "Commission") and the instructions to
Form S-8, the Registrant is not filing such documents with the Commission either
as part of this Registration Statement or as prospectuses or prospectus
supplements pursuant to Rule 424.

Item 2.     Registrant Information and Employee Plan Annual Information.

            The Registrant will send or give the documents containing the
information specified in this Item 2 to employees, officers, directors or others
as specified by Rule 428(b). In accordance with the rules and regulations of the
Commission and the instructions to Form S-8, the Registrant is not filing such
documents with the Commission either as part of this Registration Statement or
as prospectuses or prospectus supplements pursuant to Rule 424.

                                      I-1
3

                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.     Incorporation of Documents by Reference.

            The following documents and information heretofore filed with the
Commission by the Registrant are incorporated herein by reference:

            (a)   The Registrant's Annual Report on Form 10-K for the fiscal
                  year ended January 31, 1999;

            (b)   The Registrant's Quarterly Report on Form 10-Q for the fiscal
                  quarter ended May 1, 1999;

            (c)   The Registrant's Current Reports on Form 8-K filed February
                  15, 1999, Form 8-K filed March 15, 1999 and Form 8-K filed
                  June 28, 1999;

            (d)   The description of the Registrant's common stock, par value
                  $.01 per share, set forth in the Registrant's Registration
                  Statement filed under the Securities Exchange Act of 1934,
                  including any amendments or reports filed for the purpose of
                  updating such description.

            All documents subsequently filed with the Commission by the
Registrant pursuant to Section 13(a), 13(c), 14 and 15(d) of the Securities
Exchange Act of 1934, as amended, prior to the filing of a post-effective
amendment which indicates that all securities offered hereunder have been sold
or which deregisters all securities then remaining unsold under this
Registration Statement shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents. Any statement contained herein or in a document incorporated or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Registration Statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such earlier statement. Any statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute part of this
Registration Statement.

Item 4.     Description of Securities.

            Not applicable.

Item 5.     Interests of Named Experts and Counsel.

            Not applicable.

                                      II-1
4

Item 6.     Indemnification of Directors and Officers.

            The Maryland General Corporation Law permits a Maryland corporation
to include in its charter a provision limiting the liability of its directors
and officers to the corporation and its stockholders for money damages except
for liability resulting from (a) actual receipt of an improper benefit or profit
in money, property or services or (b) active and deliberate dishonesty
established by a final judgment as being material to the cause of action. The
charter of Unitrode Corporation, a Maryland corporation (the "Registrant"),
contains such a provision which eliminates such liability except (a) to the
extent that it is proved that the person actually received an improper benefit
or profit in money, property or services, for the amount of the benefit or
profit in money, property or services actually received, or (b) to the extent
that a judgment or other final adjudication adverse to the person is entered in
a proceeding based on a finding in the proceeding that the person's action, or
failure to act, was the result of active and deliberate dishonesty and was
material to the cause adjudicated in the proceeding.

            The Registrant's Amended and Re-stated By-Laws obligate it, to the
maximum extent permitted by Maryland law, to indemnify and to pay or reimburse
reasonable expenses in advance of final disposition of a proceeding to (a) any
individual who is a present or former director or officer or (b) any individual
who, while a director of the Registrant and at the request of the Registrant,
serves or has served another corporation, partnership, joint venture, trust,
employee benefit plan or any other enterprise as a director, officer, partner or
trustee of such corporation, partnership, joint venture, trust, employee benefit
plan or other enterprise. The Registrant's Amended and Re-stated By-Laws also
permit the Registrant to indemnify and advance expenses to any person who served
a predecessor of the Registrant in any of the capacities described above and to
any employee or agent of the Registrant or a predecessor of the Registrant.

            The Maryland General Corporation Law requires a corporation (unless
its charter provides otherwise, which the Registrant's charter does not) to
indemnify a director or officer who has been successful, on the merits or
otherwise, in the defense of any proceeding to which he is made a party by
reason of his service in that capacity. The Maryland General Corporation Law
permits a corporation to indemnify its present and former directors and
officers, among others, against judgments, penalties, fines, settlements and
reasonable expenses actually incurred by them in connection with any proceeding
to which they may be made a party by reason of their service in those or other
capacities unless it is established that (a) the act or omission of the director
or officer was material to the matter giving rise to the proceeding and (i) was
committed in bad faith or (ii) was the result of active and deliberate
dishonesty, (b) the director or officer actually received an improper personal
benefit in money, property or services or (c) in the case of any criminal
proceeding, the director or officer had reasonable cause to believe that the act
or omission was unlawful. However, under the Maryland General Corporation Law, a
Maryland corporation may not indemnify for an adverse judgment in a suit by or
in the right of the corporation or for a judgment of liability on the basis that
personal benefit was improperly received, unless in either case a court orders
indemnification and then only for expenses. In addition, the Maryland General
Corporation Law requires a corporation, as a condition to

                                      II-2
5

advancing reasonable expenses, to obtain (a) a written affirmation by the
director or officer of his good faith belief that he has met the standard of
conduct necessary for indemnification by the corporation and (b) a written
undertaking by him or on his behalf to repay the amount paid or reimbursed by
the corporation if it shall ultimately be determined that the standard of
conduct was not met.

            The Registrant's officers and directors are insured against certain
liabilities under a policy maintained by the Registrant with an aggregate
coverage of $10,000,000.

Item 7.     Exemption From Registration Claimed.

            Not claimed.

Item 8.     Exhibits.

4.1         Articles of Restatement of the Charter of the Registrant and
            Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3A to the Registrant's Annual Report on Form 10K
            for the fiscal year ended January 31, 1989 and incorporated herein
            by reference.

4.2         Articles Supplementary to the Charter of the Registrant, previously
            filed as Exhibits 3(A)(1) and (6) to the Registrant's Current Report
            on Form 8-K filed May 4, 1990 and incorporated herein by reference.

4.3         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3B to the Registrant's Annual Report on Form 10-K
            for fiscal year ended January 31, 1992 and incorporated herein by
            reference.

4.4         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3D to the Registrant's Annual Report on Form 10-K
            for the fiscal year ended January 31, 1998, and incorporated herein
            by reference.

4.5         Amended and Re-stated By-Laws of the Registrant.

4.6         Rights Agreement dated as of May 2, 1990 between the Registrant and
            The First National Bank of Boston as Rights Agent, previously filed
            as Exhibit 1 to the Registrant's Registration Statement on Form 8-A
            dated May 3, 1990 and incorporated herein by reference.

4.7         First Amendment, dated as of April 30, 1993, to the Rights
            Agreement, dated as of May 2, 1990, between the Registrant and The
            First National Bank of Boston, as Rights Agent, previously filed as
            Exhibit 1 to Form 8-A/A, Amendment to Registration Statement on Form
            8-A, dated May 26, 1993 and incorporated herein by reference.

                                      II-3
6

4.8         Unitrode Corporation 1999 Equity Incentive Plan, previously filed as
            Appendix A to the Registrant's Proxy Statement for its 1999 Annual
            Meeting of Stockholders on Schedule 14A, filed April 27, 1999.

4.9         Unitrode Corporation Employee Stock Purchase Plan (as amended as of
            July 6, 1999).

5.1         Opinion of Ballard Spahr Andrews & Ingersoll, LLP.

23.1        Consent of PricewaterhouseCoopers LLP.

23.2        Consent of Ernst & Young LLP.

23.3        Consent of Ballard Spahr Andrews & Ingersoll, LLP (included in
            Exhibit 5.1).

24.1        Powers of Attorney (included on page II-6 hereof).

Item 9.     Undertakings.

(a)   The undersigned Registrant hereby undertakes:

                  (1) To file, during any period in which offers or sales are
      being made, a post-effective amendment to this registration statement:

                            (i) To include any prospectus required by
            Section 10(a)(3) of the Securities Act of 1933, as amended;

                           (ii) To reflect in the prospectus any facts or events
            arising after the effective date of the registration statement (or
            the most recent post-effective amendment thereof) which,
            individually or in the aggregate, represent a fundamental change in
            the information set forth in the registration statement.
            Notwithstanding the foregoing, any increase or decrease in volume of
            securities offered (if the total dollar value of securities offered
            would not exceed that which was registered) and any deviation from
            the low or high and of the estimated maximum offering range may be
            reflected in the form of prospectus filed with the Commission
            pursuant to Rule 424(b) if, in the aggregate, the changes in volume
            and price represent no more than a 20 percent change in the maximum
            aggregate offering price set forth in the "Calculation of
            Registration Fee" table in the effective registration statement.

                          (iii) To include any material information with respect
            to the plan of distribution not previously disclosed in the
            registration statement or any material change in such information in
            the registration statement;

                                      II-4
7

      provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
      if the information required to be included in a post-effective amendment
      by those paragraphs is contained in periodic reports filed with or
      furnished to the Commission by the Registrant pursuant to Section 13 or
      15(d) of the Exchange Act that are incorporated by reference in the
      registration statement.

                  (2) That, for the purpose of determining any liability under
      the Securities Act of 1933, as amended, each such post-effective amendment
      shall be deemed to be a new registration statement relating to the
      securities offered therein, and the offering of such securities at that
      time shall be deemed to be the initial bona fide offering thereof.

                  (3) To remove from registration by means of a post-effective
      amendment any of the securities being registered which remain unsold at
      the termination of the offering.

            (b) The undersigned Registrant hereby undertakes that, for purposes
of determining any liability under the Securities Act of 1933, as amended, each
filing of the Registrant's annual report pursuant to Section 13(a) or Section
15(d) of the Exchange Act (and, where applicable, each filing of an employee
benefit plan's annual report pursuant to Section 15(d) of the Exchange Act) that
is incorporated by reference in the registration statement shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

            (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933, as amended, may be permitted to directors, officers and
controlling persons of the Registrant pursuant to the foregoing provisions, or
otherwise, the Registrant has been advised that in the opinion of the Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933, as amended, and is, therefore, unenforceable. In the event that a claim
for indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act of 1933, as amended, and will be governed by the final adjudication of such
issue.

                                      II-5
8

                                    SIGNATURES

            Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Merrimack, State of New Hampshire, on this 6th day of
July, 1999.

                                    Unitrode Corporation, a Maryland
                                    corporation (Registrant)

                                    By:   /s/ Robert J. Richardson
                                          ---------------------------------
                                          Robert J. Richardson,
                                          Chairman, President and Chief
                                          Executive Officer

                               POWER OF ATTORNEY

            KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Robert J. Richardson and Allan R.
Campbell, jointly and severally, his true and lawful attorneys-in-fact, each
with full power of substitution and resubstitution, for him and in his name,
place and stead, in any and all capacities, to sign any amendments and
supplements to this Registration Statement (including post-effective
amendments), and to file the same, with all exhibits thereto and other documents
in connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that each of said attorneys-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof.

            Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.
NAME                              TITLE                                                  DATE
/s/ Robert J. Richardson                Chairman, President and Chief Executive             July 6, 1999
-------------------------------         Officer (principal executive officer) and Director
Robert J. Richardson

/s/ John L. Kokulis                     Executive Vice President and                        July 6, 1999
-------------------------------         Chief Financial Officer
John L. Kokulis                         (principal financial and accounting
                                        officer)

/s/ Robert L. Gable                     Director                                            July 6, 1999
-------------------------------
Robert L. Gable

/s/ Dietrich R. Erdmann                 Director                                            July 6, 1999
-------------------------------
Dietrich R. Erdmann

/s/ William W.R. Elder                  Director                                            July 6, 1999
-------------------------------
William W.R. Elder

/s/ Louis E. Lataif                     Director                                            July 6, 1999
-------------------------------
Louis E. Lataif

/s/ James T. Vanderslice                Director                                            July 6, 1999
-------------------------------
James T. Vanderslice
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9

                                 EXHIBIT INDEX
EXHIBIT
  NO.                        DESCRIPTION OF EXHIBIT
4.1         Articles of Restatement of the Charter of the Registrant and
            Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3A to the Registrant's Annual Report on Form 10K
            for the fiscal year ended January 31, 1989 and incorporated herein
            by reference.

4.2         Articles Supplementary to the Charter of the Registrant, previously
            filed as Exhibits 3(A)(1) and (6) to the Registrant's Current Report
            on Form 8-K filed May 4, 1990 and incorporated herein by reference.

4.3         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3B to the Registrant's Annual Report on Form 10-K
            for fiscal year ended January 31, 1992 and incorporated herein by
            reference.

4.4         Articles of Amendment to the Charter of the Registrant, previously
            filed as Exhibit 3D to the Company's Annual Report on Form 10-K for
            the fiscal year ended January 31, 1998, and incorporated herein by
            reference.

4.5         Amended and Re-stated By-Laws of the Registrant.

4.6         Rights Agreement dated as of May 2, 1990 between the Registrant and
            The First National Bank of Boston as Rights Agent, previously filed
            as Exhibit 1 to the
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Registrant's Registration Statement on Form 8-A dated May 3, 1990
            and incorporated herein by reference.

4.7         First Amendment, dated as of April 30, 1993, to the Rights
            Agreement, dated as of May 2, 1990, between the Company and the
            First National Bank of Boston, as Rights Agent, previously filed as
            Exhibit 1 to Form 8-A/A, Amendment to Registration Statement on Form
            8-A, dated May 26, 1993 and incorporated herein by reference.

4.8         Unitrode Corporation 1999 Equity Incentive Plan (as amended as of
            July 6, 1999).

4.9         Unitrode Corporation Employee Stock Purchase Plan, previously filed
            as Appendix B to the Proxy Statement for the 1999 Annual Meeting the
            Stockholders on Schedule 14A, filed April 27, 1999.

5.1         Opinion of Ballard Spahr Andrews & Ingersoll, LLP.

23.1        Consent of PricewaterhouseCoopers LLP.

23.2        Consent of Ernst & Young LLP.

23.3        Consent of Ballard Spahr Andrews & Ingersoll, LLP (included in
            Exhibit 5.1).

24.1        Powers of Attorney (included on page II-6 hereof).
II-8