<PAGE>   1
                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON D.C. 20549

                                    FORM 10-Q


(Mark One)
/X/ QUARTERLY REPORT PURSUANT TO SECTION 13 or 15(d) OF THE SECURITIES
    EXCHANGE ACT OF 1934
                  For the quarterly period ended AUGUST 2, 1997

                                       OR

/ / TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
    EXCHANGE ACT OF 1934
                  For the transition period from ________ to __________


                      Commission file number       1-5609


                              UNITRODE CORPORATION
             (Exact name of registrant as specified in its charter)

             MARYLAND                                     04-2271186
   (State or other jurisdiction of                     (I.R.S. Employer
   incorporation or organization)                      Identification No.)

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

          Registrant's telephone number, including area code: (603) 424-2410



Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of Securities Exchange Act of 1934 during the
preceding 12 months (or for such shorter period that the registrant was required
to file such reports), and (2) has been subject to such filing requirements for
the past 90 days. Yes   X    No
                      -----     -----
 
There were 11,807,326 shares of common stock outstanding as of August 2, 1997.



                                       -1-


<PAGE>   2



                          PART I. FINANCIAL INFORMATION

Item 1. Financial Statements


               Unitrode Corporation and Consolidated Subsidiaries
                                 Balance Sheets
                                 (in thousands)


<TABLE>
<CAPTION>
                                              August 2, 1997   January 31, 1997
Assets                                          (Unaudited)
--------------------------------------------------------------------------------
<S>                                             <C>             <C>     
Current assets:
  Cash and cash equivalents                     $ 46,919        $ 52,012
  Accounts receivable, net of allowance
     of $403 in August, 1997
     and $383 in January, 1997                    27,656          15,864
  Notes receivable                                   754             905
  Inventories:
     Raw materials                                   739           1,282
     Work in process                               8,724           6,303
     Finished goods                                1,714           3,365
                                                --------        --------
       Total inventory                            11,177          10,950
                                                --------        --------

  Deferred income taxes                            4,303           3,322
  Prepaid expenses and other
    current assets                                 2,560           4,410
                                                --------        --------

     Total current assets                         93,369          87,463
                                                --------        --------

Property, plant and equipment, at cost           121,644          93,725
  Less accumulated depreciation                   57,146          52,037
                                                --------        --------
    Property, plant and equipment, net            64,498          41,688
                                                --------        --------

Notes and other receivables, net of
 discount                                          3,098           3,514
Deferred income taxes                                723           1,191
Restricted cash and investments                      947             812
Excess of cost over net assets acquired,
   net of accumulated amortization of
   $2,252 in August, 1997 and
   $2,110 in January, 1997                         1,838           1,980
Other assets and deferred charges                  4,428           5,755
                                                --------        --------

Total assets                                    $168,901        $142,403
                                                ========        ========
</TABLE>




The accompanying notes are an integral part of the financial statements.

                                       -2-
<PAGE>   3



               Unitrode Corporation and Consolidated Subsidiaries
                                 Balance Sheets
                      (in thousands except per share data)


<TABLE>
<CAPTION>
                                              August 2, 1997    January 31, 1997
Liabilities and Stockholders' Equity            (Unaudited)
--------------------------------------------------------------------------------
<S>                                              <C>               <C>     
Current liabilities:
  Accounts payable                               $ 10,924          $  8,768
  Income taxes payable                              3,335             4,346
  Accrued employee compensation
     and benefits                                   8,921             4,416
  Other current liabilities                         9,672             7,350
                                                 --------          --------

     Total current liabilities                     32,852            24,880
                                                 --------          --------

Deferred income taxes                               1,129             1,151
Other long-term liabilities                           858               819
                                                 --------          --------

     Total liabilities                             34,839            26,850
                                                 --------          --------

Stockholders' equity:
  Common stock, $.20 par value;
    Authorized - 30,000 shares
    Issued - 11,807 in August, 1997 and
             11,633 in January, 1997                2,361             2,327
  Additional paid-in capital                       32,007            28,102
  Retained earnings                                99,778            85,255
                                                 --------          --------
                                                  134,146           115,684

Less:
  Deferred compensation                                84               131
                                                 --------          --------

     Total stockholders' equity                   134,062           115,553
                                                 --------          --------

Total liabilities and
    stockholders' equity                         $168,901          $142,403
                                                 ========          ========
</TABLE>

The accompanying notes are an integral part of the financial statements.

                                       -3-
<PAGE>   4
               Unitrode Corporation and Consolidated Subsidiaries
                            Statements of Operations
                                   (Unaudited)
                      (in thousands except per share data)


<TABLE>
<CAPTION>
For the three months ended                   August 2, 1997        July 27, 1996
--------------------------------------------------------------------------------

<S>                                           <C>                    <C>    
Net revenues                                  $48,178                $30,008
Cost of revenues                               22,624                 14,102
                                              -------                -------

  Gross profit                                 25,554                 15,906
                                              -------                -------

Operating expenses:
  Research and development                      4,409                  4,030
  Selling, general and administrative           7,863                  5,275
  New fab pre-operating expenses                1,631                      -
                                              -------                -------
    Total operating expenses                   13,903                  9,305
                                              -------                -------

Income from operations                         11,651                  6,601
                                              -------                -------

Other income (expense):
  Royalty income                                1,047                    561
  Non-operating income (expense), net            (472)                    39
  Interest income, net                            655                    454
                                              -------                -------

    Total other income                          1,230                  1,054
                                              -------                -------

Income before income tax provision             12,881                  7,655

Income tax provision                            4,763                  2,947
                                              -------                -------

Net income                                     $8,118                 $4,708
                                              =======                =======

Earnings per common share:
  Net income                                  $   .65                $   .40
                                              =======                =======

Average common and common equivalent
  shares outstanding                           12,456                 11,838
                                              =======                 ======

</TABLE>


The accompanying notes are an integral part of the financial statements.

                                       -4-
<PAGE>   5

               Unitrode Corporation and Consolidated Subsidiaries
                            Statements of Operations
                                   (Unaudited)
                      (in thousands except per share data)




<TABLE>
<CAPTION>
For the six months ended                 August 2, 1997      July 27, 1996
--------------------------------------------------------------------------

<S>                                            <C>                <C>     
Net revenues                                   $ 89,018           $ 64,229
Cost of revenues                                 41,770             30,118
                                               --------           --------

  Gross profit                                   47,248             34,111
                                               --------           --------

Operating expenses:
  Research and development                        8,731              8,480
  Selling, general and administrative            14,590             11,636
  New fab pre-operating expenses                  3,145                 --
                                               --------           --------

    Total operating expenses                     26,466             20,116
                                               --------           --------

Income from operations                           20,782             13,995
                                               --------           --------

Other income (expense):
  Royalty income                                  1,650              1,255
  Non-operating income (expense), net              (297)                26
  Interest income, net                            1,266                863
                                               --------           --------

    Total other income                            2,619              2,144
                                               --------           --------

Income before income tax provision               23,401             16,139

Income tax provision                              8,697              6,170
                                               --------           --------

Net income                                     $ 14,704           $  9,969
                                               ========           ========



Earnings per common share:
   Net income                                  $   1.19           $    .84
                                               ========           ========

Average common and common equivalent
  shares outstanding                             12,326             11,846
                                               ========           ========
</TABLE>


The accompanying notes are an integral part of the financial statements.

                                       -5-
<PAGE>   6



               Unitrode Corporation and Consolidated Subsidiaries
                            Statements of Cash Flows
                                   (Unaudited)
                                 (in thousands)
<TABLE>
<CAPTION>
For the six months ended                                  August 2, 1997      July 27, 1996
-------------------------------------------------------------------------------------------
<S>                                                           <C>             <C>     
Cash flows from operating activities:
   Net income                                                 $ 14,704        $  9,969
   Adjustments to reconcile net income to
   net cash provided by operating activities:
     Depreciation and amortization                               5,545           5,534
     Deferred compensation                                          47              77
     Writedown of assets                                         1,105              --
     Deferred income taxes                                        (535)             50
     Other, net                                                    (87)            152
     (Increase) decrease in assets:
       Accounts receivable                                     (11,792)          1,711
       Inventories                                                (227)         (2,073)
       Other current and long-term assets                          197             200
     Increase (decrease) in liabilities:
       Accounts payable                                          2,156            (845)
       Income taxes payable                                        730            (763)
       Accrued employee compensation and benefits                4,505          (4,377)
       Other current and long-term liabilities                   2,361            (171)
                                                              --------        --------
          Total adjustments                                      4,005            (505)
                                                              --------        --------
       Net cash provided by operating activities                18,709           9,464
                                                              --------        --------

Cash flows from investing activities:
   Property, plant and equipment and deposits                  (26,331)         (8,162)
   Proceeds on sale of assets                                       94              84
   Repayment of notes receivable                                   578             480
   Restricted cash and investments                                (160)         (1,644)
   Maturities of short-term investments                             --           4,345
   Purchases of short-term investments                              --          (4,369)
                                                              --------        --------
       Net cash used by investing activities                   (25,819)         (9,266)
                                                              --------        --------

Cash flows from financing activities:
   Proceeds from exercise of stock options and warrants          2,256             719
   Purchase of common stock                                       (239)            (92)
                                                              --------        --------
       Net cash provided by financing activities                 2,017             627
                                                              --------        --------

Net increase (decrease) in cash and cash equivalents            (5,093)            825
Cash and cash equivalents at beginning of period                52,012          36,228
                                                              --------        --------
Cash and cash equivalents at end of period                    $ 46,919        $ 37,053
                                                              ========        ========

Supplemental information:
     Interest paid                                            $     71        $     43
     Income taxes paid, net of tax refunds                       8,502           6,894
</TABLE>


The accompanying notes are an integral part of the financial statements.

                                       -6-
<PAGE>   7



               Unitrode Corporation and Consolidated Subsidiaries
                          Notes to Financial Statements
                                 August 2, 1997
                                   (Unaudited)


Note 1 - Basis of Presentation
------------------------------

The accompanying unaudited consolidated financial statements have been prepared
in accordance with generally accepted accounting principles for interim
financial information and pursuant to the rules and regulations of the
Securities and Exchange Commission. Accordingly, they do not include all of the
information and footnotes required by generally accepted accounting principles
for complete financial statements. For further information, refer to the
consolidated financial statements and footnotes included in the annual report on
Form 10-K of Unitrode Corporation (the "Company") for the year ended January 31,
1997.

In the opinion of management, all adjustments considered necessary for a fair
presentation have been included. Operating results for the six-month period
ended August 2, 1997 are not necessarily indicative of the results that may be
expected for the year ended January 31, 1998. Certain amounts for fiscal year
1997 have been reclassified to conform with presentation of similar amounts in
fiscal year 1998.


Note 2 - New Accounting Standards
---------------------------------

In February, 1997, the Financial Accounting Standards Board issued SFAS No. 128,
"Earnings per Share", which requires the presentation of basic and diluted
earnings per share. Basic earnings per share excludes dilutive securities such
as stock options and is computed by dividing net income by the weighted-average
number of common shares outstanding for the period. Diluted earnings per share
is computed similarly to the existing rules for fully diluted earnings per
share. The Company will adopt SFAS No. 128 as of January 31, 1998 and will
restate all prior period earnings per share data presented. Basic earnings per
share calculated under the provisions of SFAS No. 128 for the three months ended
August 2, 1997 and July 27, 1996 would have been $.69 and $.41 respectively, and
for the six months ended August 2, 1997 and July 27, 1996 would have been $1.25
and $.87, respectively.

                                       -7-
<PAGE>   8



Item 2. Management's Discussion and Analysis of Financial Condition and Results
of Operations

RESULTS OF OPERATIONS
---------------------

Three Months Ended August 2, 1997 versus Three Months Ended July 27, 1996

Net sales for the quarter ended August 2, 1997 were $48.2 million compared with
$30.0 million in the previous year's second quarter, an increase of $18.2
million or 61%. This sales increase was due primarily to a higher level of
demand for the Company's power management and interface products, resulting from
strength in the electronic data and computer peripherals markets. Product sales
to one of the Company's customers represented approximately 21% of sales in the
second quarter of fiscal year 1998 compared to 30% in the same period in fiscal
year 1997. Approximately 63% of sales in the second quarter were international
compared with 66% in the prior year.

Gross profit as a percentage of net sales remained unchanged at 53% compared to
the prior year. Lower unit costs resulting from greater capacity utilization at
the Company's wafer fabrication facilities were substantially offset by
increased sales of new products having fixed unit costs manufactured by GMT
Microelectronics Corporation ("GMT"), a foundry in which the Company has a
strategic relationship. The Company expects to maintain gross margin at
approximately the current rate for the rest of the fiscal year after taking into
consideration the combination of additional capacity at GMT and the conversion
of part of the 4" existing Merrimack facility to BiCMOS processes.

Research and development expenses were 9% of net sales, or $4.4 million,
compared with 13%, or $4.0 million, in the prior year. The percentage decrease
for research and development expenses was principally due to the increased sales
volume. Selling, general and administrative expenses were 16% of net sales, or
$7.9 million, compared with 18%, or $5.3 million, in the previous year's second
quarter. The increase of $2.6 million was primarily due to incentive
compensation accruals and sales commissions.

During fiscal year 1998, the Company estimates spending approximately $6.0
million in pre-operating expenses associated with the new 6" BiCMOS wafer
fabrication facility in Merrimack, New Hampshire. Pre-operating costs, which are
incurred prior to the commencement of production, relate primarily to the
recruitment and training of personnel as well as the qualification of equipment
and manufacturing processes to meet design, test, and reliability specifications
for production. In the second quarter of fiscal year 1998, the Company incurred
$1.6 million in pre-operating expenses.

Royalty income increased by $486,000 principally due to a lump-sum receipt from
a new licensee in this fiscal quarter.

The consolidated effective tax rate for the quarter ended August 2, 1997 was
37.0% compared with 38.5% for the quarter ended July 27, 1996. This decrease was
due primarily to a reduction in the state income tax rate for the Company and
the tax rate applicable to the Company's foreign operations.

Net income increased 72% from $4.7 million, or $.40 per share, for the second
quarter of fiscal year 1997 compared to $8.1 million, or $.65 per share, for the
second quarter of fiscal year 1998.

                                       -8-
<PAGE>   9

RESULTS OF OPERATIONS (CONTINUED)
---------------------

Six Months Ended August 2, 1997 versus Six Months Ended July 27, 1996

Net sales for the six months ended August 2, 1997 were $89.0 million compared
with $64.2 million in the previous year's six month period, an increase of $24.8
million or 39%. This sales increase was due primarily to a higher level of
demand for the Company's power management and interface products, resulting from
strength in the electronic data and computer peripherals markets. Product sales
to one of the Company's customers represented approximately 24% of sales for the
six months ended August 2, 1997 compared to 28% for the six months ended July
27, 1996. Approximately 65% of sales in the first six months of both fiscal 
years 1998 and 1997 were international.

Gross profit as a percentage of net sales remained unchanged at 53% when
compared to the prior year. Lower unit costs resulting from greater capacity
utilization at the Company's wafer fabrication facilities were substantially
offset by increased sales of new products having fixed unit costs manufactured
by GMT Microelectronics Corporation.

Research and development expenses were 10% of net sales, or $8.7 million,
compared with 13%, or $8.5 million, in the prior year. The percentage decrease
for research and development expenses was principally due to the increased sales
volume. Selling, general and administrative expenses were 16% of net sales, or
$14.6 million, compared with 18%, or $11.6 million, in the previous year. This
increase of $3.0 million was due primarily to incentive compensation accruals
and sales commissions.

During the first six months of fiscal year 1998, the Company incurred $3.1
million in pre-operating expenses associated with the new 6" BiCMOS wafer
fabrication facility in Merrimack, New Hampshire.

Royalty income increased by $395,000 principally due to a lump-sum receipt from
a new licensee in the second quarter of fiscal year 1998. Interest income
increased by $403,000 primarily due to the increase in the Company's cash and
cash equivalents.

The consolidated effective tax rate for the six months ended August 2, 1997 was
37.2% compared with 38.2% for the six months ended July 27, 1996. This decrease
was due primarily to a reduction in the state income tax rate for the Company
and the tax rate applicable to the Company's foreign operations.

Net income for the first six months increased 47% from $10.0 million, or $.84
per share, for fiscal year 1997 compared to $14.7 million, or $1.19 per share,
for fiscal year 1998.

                                       -9-
<PAGE>   10
FINANCIAL CONDITION
-------------------

Cash and short-term investments at August 2, 1997 decreased by $5.1 million to
$46.9 million since the beginning of fiscal year 1998. The principal sources of
cash were $18.7 million from operating activities and $2.3 million in proceeds
from exercises of stock options and warrants offset by $26.3 million in capital
expenditures.

In fiscal year 1998, the Company expects to spend a total of approximately $44
million in capital expenditures consisting of $25 million for the new wafer
fabrication facility and $19 million to support ongoing operations, primarily
increased testing capacity. The construction of the new 6" BiCMOS wafer
fabrication facility in Merrimack, New Hampshire is completed. Qualification of
equipment and manufacturing processes are scheduled for the remainder of fiscal
year 1998. The new fab is expected to become operational in the first quarter of
fiscal year 1999. It is anticipated that the Company's operating cash needs for
fiscal year 1998, including planned capital expenditures, will be met by
internally generated funds and available cash.

The ratio of current assets to current liabilities was 2.84:1 at August 2, 1997
compared with 3.52:1 at January 31, 1997. Working capital of $60.5 million at
August 2, 1997 decreased by $2.1 million from January 31, 1997. Accounts
receivable at August 2, 1997 increased by $11.8 million from January 31, 1997
primarily due to the higher level of sales. Receivable day sales outstanding
were 51 days at August 2, 1997 compared to 44 days at January 31, 1997 and 52
days at May 3, 1997. Accounts payable and other current liabilities at August 2,
1997 increased by a total of $4.5 million from January 31, 1997, primarily due
to obligations for capital assets and pre-operating costs related to the new
wafer fabrication expansion program. Accrued employee compensation and benefits
has increased by $4.5 million since year-end primarily due to incentive
compensation accruals.

On November 21, 1995, the Company issued 247,883 warrants to purchase the
Company's common stock as part of the final settlement of a class action
lawsuit. Each warrant entitles the holder to purchase one share of the Company's
common stock at $28.467 per share. These warrants expired on August 21, 1997.
Upon expiration, the Company received $6.2 million in proceeds from the exercise
of 219,034 warrants.

NEW ACCOUNTING STANDARDS
------------------------

See Note 2 in the Company's consolidated financial statements for a discussion
of recently issued accounting standards.









                                      -10-


<PAGE>   11



FORWARD-LOOKING INFORMATION
---------------------------

The Private Securities Litigation Reform Act of 1995 ("the Act") provides a new
"safe harbor" for forward-looking statements so long as those statements are
identified as forward-looking and are accompanied by meaningful cautionary
statements identifying important factors that could cause actual results to
differ materially from those discussed in the statement. The Company desires to
take advantage of the new "safe harbor" provisions of the Act. Certain
information contained herein, particularly the information appearing under the
headings "Results of Operations" and "Financial Condition" are forward-looking.
Information regarding certain important factors that could cause actual results
of operations or outcomes of other events to differ materially from any such
forward-looking statement appear together with such statement, and/or elsewhere
herein. This information should be read in conjunction with the Company's annual
report on Form 10-K for the year ended January 31, 1997, particularly the
information appearing under the heading "Factors Affecting Future Results" in
the "Management's Discussion and Analysis of Financial Condition and Results of
Operations" section of the report.










                                      -11-

<PAGE>   12



                           PART II. OTHER INFORMATION
               Unitrode Corporation and Consolidated Subsidiaries
                                 August 2, 1997

Item 1.  Legal Proceedings
--------------------------

In June, 1997, Linear Technology Corporation ("LTC") filed a complaint in U.S.
District Court for the Northern District of California (San Jose Division)
alleging that certain products of the Company and products of four other
defendants infringe an LTC patent. The complaint seeks damages and an injunction
against infringement of the patent. The Company has denied any infringement and
has filed a counterclaim seeking that the patent be declared invalid. The
Company believes that the resolution of this action will not have a materially
adverse effect on the Company's financial condition or results of operations.

Item 2.  Changes In The Rights Of The Company's Security Holders
----------------------------------------------------------------

None.

Item 3.  Defaults upon Senior Securities
----------------------------------------

Not Applicable.


Item 4.  Submission of Matters to a Vote of Security Holders
------------------------------------------------------------

The Registrant's annual meeting of stockholders was held on June 2, 1997, at
which two matters were submitted to a vote of security holders: (1) the election
of Edward H. Browder and Kenneth Hecht as directors of the Registrant, each for
a three-year term ending in 2000; and, (2) the approval and ratification of an
amendment to the Registrant's 1992 Employee Stock Option Plan to increase the
number of shares of common stock available for issuance under the Plan from
2,000,000 shares to 3,000,000 shares. As of April 4, 1997, the record date for
said meeting, there were outstanding 11,710,174 shares of the Registrant's
common stock entitled to vote at the meeting. At such meeting, the holders of
10,638,004 shares were represented in person or by proxy, constituting a quorum.
At such meeting, the vote with respect to the matters proposed to the
stockholders was as follows:

      (1) Election Of Directors:
      --------------------------
                                  For           Withheld
                                  ---           --------

      Mr. Browder             10,383,011        254,993
      Mr. Hecht               10,385,046        252,958

      (2) Approval and Ratification of Amendment to the Unitrode 1992
          -----------------------------------------------------------
          Employee Stock Option Plan:
          ---------------------------

                                  For           Against           Abstain
                                  ---           -------           -------

                              6,230,852         2,730,531         105,683

Item 5.  Other Information
--------------------------

On August 5, 1997, the Company announced a special meeting of stockholders to be
held on September 29, 1997 for the purposes of considering and voting on an
increase in the total number of authorized shares from 31,000,000 to 61,000,000
and the number of authorized shares of common stock from 30,000,000 to
60,000,000. Stockholders will also consider and vote on a proposal to reduce the
par value of the Company's common stock and preferred stock to $.01 per share.
Contingent upon stockholder approval of additional authorized shares, the Board
approved a two-for-one stock split in the form of a dividend of one additional
share of common stock for each outstanding share of common stock to stockholders
of record as of the close of business on October 6, 1997.

                                      -12-
<PAGE>   13

               Unitrode Corporation and Consolidated Subsidiaries
                                 August 2, 1997


Item 6.  Exhibits and Reports on Form 8-K
-----------------------------------------

      (a)   Exhibits
            --------

            Exhibit 11 - Computation of Primary and Fully Diluted Earnings per
            Share

            Exhibit 27 - Financial Data Schedule

      (b)   REPORTS ON FORM 8-K: No reports on Form 8-K were filed by the
            Registrant during the second quarter of the fiscal year ended
            January 31, 1998.








                                      -13-
<PAGE>   14

               Unitrode Corporation and Consolidated Subsidiaries
                                 August 2, 1997

                                   SIGNATURES


      Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.



                                          UNITRODE CORPORATION



September 15, 1997               /s/ Robert L. Gable
------------------               ----------------------------------------
Date                             Robert L. Gable
                                 Chairman and Chief Executive Officer


September 15, 1997               /s/ Cosmo S. Trapani
------------------               ----------------------------------------
Date                             Cosmo S. Trapani
                                 Executive Vice President and
                                 Chief Financial Officer
                                 (Principal Financial and Accounting
                                 Officer)








                                      -14-