SECURITIES AND EXCHANGE COMMISSION 
                           WASHINGTON, D.C. 20549 
  
  
                                  FORM 8-K 
                               CURRENT REPORT 
  
  
                   Pursuant to Section 13 or 15(d) of the 
                      Securities Exchange Act of 1934 
  
  
                               August 3, 1998 
                     (Date of earliest event reported) 
  
  
                           UNITRODE CORPORATION
           (Exact name of Registrant as specified in its charter) 
  
  
  Maryland                    1-5609                    04-2271188   
 (State of              (Commission File No.)          (IRS Employer 
 Incorporation)                                      Identification No.) 
  
  
                7 Continental Boulevard, Merrimack, NH 03054        
        (Address of principal executive offices, including zip code) 
  
  
                                (603) 424-2410                  
            (Registrant's telephone number, including area code) 
  
  
                                 Not Applicable                      
       (Former name or former address, if changed since last report) 
  
  
  

 Item 2.   Acquisition or Disposition of Assets. 
  
 (a)  Acquisition of BENCHMARQ Microelectronics, Inc.  Pursuant to the terms
 of the previously reported Agreement and Plan of Merger, dated as of March
 2, 1998 (the "Merger Agreement") and the amendment thereto, dated as of
 June 23, 1998 (the "Amendment"), by and among Unitrode Corporation, a
 Maryland corporation ("Unitrode"), Merrimack Corporation, a Delaware
 corporation and a wholly owned subsidiary of Unitrode ("Sub") and BENCHMARQ
 Microelectronics, Inc., a Delaware corporation ("BENCHMARQ"), on August 3,
 1998, Sub merged with and into BENCHMARQ (the "Merger"), with BENCHMARQ
 surviving the Merger as a wholly owned subsidiary of Unitrode.  At the
 effective time of the Merger (the "Effective Time"), the separate existence
 of Sub ceased, and BENCHMARQ became a wholly-owned subsidiary of Unitrode. 
 At the Effective Time, each share of common stock, par value $.001 per
 share, of BENCHMARQ ("BENCHMARQ Common Stock") outstanding immediately
 prior thereto (other than shares held by BENCHMARQ as treasury shares or by
 Unitrode or any subsidiaries of BENCHMARQ or Unitrode) was converted into
 the right to receive one share of common stock, par value $.01 per share,
 of Unitrode ("Unitrode Common Stock").  In the Merger, each option to
 purchase BENCHMARQ Common Stock (each, a "BENCHMARQ Option") outstanding
 immediately prior to the Effective Time was assumed by Unitrode and
 converted into an option to purchase one share of Unitrode Common Stock
 (each, a "Unitrode Option").  Unitrode expects to issue approximately
 8,582,047 shares of Unitrode Common Stock in connection with the Merger,
 including shares issuable pursuant to BENCHMARQ Options which are being
 converted into Unitrode Options. 
  
      The foregoing description of the terms and provisions of the Merger
 Agreement, as amended, is qualified in its entirety by reference to the
 Merger Agreement, as amended, together with the respective exhibits
 thereto, and is hereby incorporated by reference herein. 
  
 (b)  Assets constituting plant, equipment or other physical property
 acquired by Unitrode in the Merger were used by BENCHMARQ in design,
 manufacture and marketing of integrated circuits and electronic modules for
 portable, power-sensitive electronic applications.  Unitrode currently
 intends to use these assets in the same manner in which they were used
 prior to Unitrode's acquisition of BENCHMARQ. 
  
 Item 7.   Financial Statement, Pro Forma Financial Information and
           Exhibits. 
  
 (a)       Financial Statements of Business Acquired.  To be filed by
           amendment to this Form 8-K within 60 days. 
  
 (b)       Pro Forma Financial Information.  To be filed by amendment to
           this Form 8-K within 60 days. 
  
 (c)       Exhibits. 

  
 Exhibit No.              Description 
  
    2.1         Agreement and Plan of Merger, dated as of March 2, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. 
                 
    2.2         Amendment to Merger Agreement, dated as of June 23, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. 
  
    99.1        Form of Press Release issued by Unitrode dated August 3,
                1998. 



                                 SIGNATURE 
  
           Pursuant to the requirements of the Securities Exchange Act of
 1934, as amended, the Registrant has duly caused this report to be signed
 on its behalf by the undersigned hereunto duly authorized. 
  
  
                                   UNITRODE CORPORATION 
  
  
                                   By: /s/ Allan R. Campbell 
                                      ---------------------------------
                                       Allan R. Campbell 
                                       Senior Vice President,
                                       General Counsel and Secretary
  
  
 Date:  August 4, 1998



  
                               Exhibit Index 
  
 Exhibit No.             Description 

    2.1         Agreement and Plan of Merger, dated as of March 2, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. (incorporated by reference
                to Unitrode's Current Report on Form 8-K dated February 28,
                1998). 
  
    2.2         Amendment to Merger Agreement, dated as of June 23, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. (incorporated by reference
                to Unitrode's Current Report on Form 8-K dated June 23,
                1998, as amended by Unitrode's Form 8-K/A dated June 23,
                1998). 
  
    99.1        Form of Press Release issued by Unitrode dated August 3,
                1998.
[{"type": "8-K", "sequence": "1", "secsgml_size_bytes": 6190}]
{"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": "8-K", "act": "34", "file-number": "000-20563", "film-number": "98676826"}, "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"}}
SECURITIES AND EXCHANGE COMMISSION 
                           WASHINGTON, D.C. 20549 
  
  
                                  FORM 8-K 
                               CURRENT REPORT 
  
  
                   Pursuant to Section 13 or 15(d) of the 
                      Securities Exchange Act of 1934 
  
  
                               August 3, 1998 
                     (Date of earliest event reported) 
  
  
                           UNITRODE CORPORATION
           (Exact name of Registrant as specified in its charter) 
  
  
  Maryland                    1-5609                    04-2271188   
 (State of              (Commission File No.)          (IRS Employer 
 Incorporation)                                      Identification No.) 
  
  
                7 Continental Boulevard, Merrimack, NH 03054        
        (Address of principal executive offices, including zip code) 
  
  
                                (603) 424-2410                  
            (Registrant's telephone number, including area code) 
  
  
                                 Not Applicable                      
       (Former name or former address, if changed since last report) 
  
  
  

 Item 2.   Acquisition or Disposition of Assets. 
  
 (a)  Acquisition of BENCHMARQ Microelectronics, Inc.  Pursuant to the terms
 of the previously reported Agreement and Plan of Merger, dated as of March
 2, 1998 (the "Merger Agreement") and the amendment thereto, dated as of
 June 23, 1998 (the "Amendment"), by and among Unitrode Corporation, a
 Maryland corporation ("Unitrode"), Merrimack Corporation, a Delaware
 corporation and a wholly owned subsidiary of Unitrode ("Sub") and BENCHMARQ
 Microelectronics, Inc., a Delaware corporation ("BENCHMARQ"), on August 3,
 1998, Sub merged with and into BENCHMARQ (the "Merger"), with BENCHMARQ
 surviving the Merger as a wholly owned subsidiary of Unitrode.  At the
 effective time of the Merger (the "Effective Time"), the separate existence
 of Sub ceased, and BENCHMARQ became a wholly-owned subsidiary of Unitrode. 
 At the Effective Time, each share of common stock, par value $.001 per
 share, of BENCHMARQ ("BENCHMARQ Common Stock") outstanding immediately
 prior thereto (other than shares held by BENCHMARQ as treasury shares or by
 Unitrode or any subsidiaries of BENCHMARQ or Unitrode) was converted into
 the right to receive one share of common stock, par value $.01 per share,
 of Unitrode ("Unitrode Common Stock").  In the Merger, each option to
 purchase BENCHMARQ Common Stock (each, a "BENCHMARQ Option") outstanding
 immediately prior to the Effective Time was assumed by Unitrode and
 converted into an option to purchase one share of Unitrode Common Stock
 (each, a "Unitrode Option").  Unitrode expects to issue approximately
 8,582,047 shares of Unitrode Common Stock in connection with the Merger,
 including shares issuable pursuant to BENCHMARQ Options which are being
 converted into Unitrode Options. 
  
      The foregoing description of the terms and provisions of the Merger
 Agreement, as amended, is qualified in its entirety by reference to the
 Merger Agreement, as amended, together with the respective exhibits
 thereto, and is hereby incorporated by reference herein. 
  
 (b)  Assets constituting plant, equipment or other physical property
 acquired by Unitrode in the Merger were used by BENCHMARQ in design,
 manufacture and marketing of integrated circuits and electronic modules for
 portable, power-sensitive electronic applications.  Unitrode currently
 intends to use these assets in the same manner in which they were used
 prior to Unitrode's acquisition of BENCHMARQ. 
  
 Item 7.   Financial Statement, Pro Forma Financial Information and
           Exhibits. 
  
 (a)       Financial Statements of Business Acquired.  To be filed by
           amendment to this Form 8-K within 60 days. 
  
 (b)       Pro Forma Financial Information.  To be filed by amendment to
           this Form 8-K within 60 days. 
  
 (c)       Exhibits. 

  
 Exhibit No.              Description 
  
    2.1         Agreement and Plan of Merger, dated as of March 2, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. 
                 
    2.2         Amendment to Merger Agreement, dated as of June 23, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. 
  
    99.1        Form of Press Release issued by Unitrode dated August 3,
                1998. 

                                 SIGNATURE 
  
           Pursuant to the requirements of the Securities Exchange Act of
 1934, as amended, the Registrant has duly caused this report to be signed
 on its behalf by the undersigned hereunto duly authorized. 
  
  
                                   UNITRODE CORPORATION 
  
  
                                   By: /s/ Allan R. Campbell 
                                      ---------------------------------
                                       Allan R. Campbell 
                                       Senior Vice President,
                                       General Counsel and Secretary
  
  
 Date:  August 4, 1998

  
                               Exhibit Index 
  
 Exhibit No.             Description 

    2.1         Agreement and Plan of Merger, dated as of March 2, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. (incorporated by reference
                to Unitrode's Current Report on Form 8-K dated February 28,
                1998). 
  
    2.2         Amendment to Merger Agreement, dated as of June 23, 1998, by
                and among Unitrode Corporation, Merrimack Corporation and
                BENCHMARQ Microelectronics, Inc. (incorporated by reference
                to Unitrode's Current Report on Form 8-K dated June 23,
                1998, as amended by Unitrode's Form 8-K/A dated June 23,
                1998). 
  
    99.1        Form of Press Release issued by Unitrode dated August 3,
                1998.