Exhibit 4.3

                               FIRST AMENDMENT TO
                                RIGHTS AGREEMENT

          THIS  AMENDMENT  (the  "Amendment"),  dated as of January 28, 2001, is
between  Dallas   Semiconductor   Corporation,   a  Delaware   corporation  (the
"Company"),  and Mellon  Investor  Services,  LLC (formerly known as ChaseMellon
Shareholder Services, L.L.C.), a New Jersey limited liability company, as Rights
Agent (the "Rights Agent").

                                    Recitals

          A. The Company and the Rights Agent are parties to a Rights Agreement,
dated as of September 10, 1999 (the "Rights Agreement").

          B.  MAXIM   Integrated   Products,   Inc.,  a  Delaware   corporation,
("Parent"),   MI  Acquisition  Sub,  Inc.,  a  Delaware   corporation   ("Merger
Subsidiary"),  and the Company have entered into an Agreement and Plan of Merger
(the  "Merger  Agreement"),  dated  January 28,  2001,  pursuant to which Merger
Subsidiary  will be merged  with and into the  Company,  with the Company as the
surviving corporation (the "Merger").

          C. The Board of  Directors  (the  "Board") of the Company has approved
the Merger Agreement and the Merger.

         D.  Pursuant  to  Section  27 of the  Rights  Agreement,  the Board has
determined  that in  connection  with the  Merger  Agreement  and the  Merger an
amendment to the Rights Agreement as set forth herein is necessary and desirable
and the  Company  and the Rights  Agent  desire to evidence  such  amendment  in
writing.

         Accordingly, the parties agree as follows:

1.       Amendment of Section 1.

          (a)       Section 1(a) of the Rights  Agreement  is hereby  amended to
                    add the following sentence at the end thereof:

                    "Notwithstanding anything in this Agreement to the contrary,
                    neither  MAXIM   Integrated   Products,   Inc.,  a  Delaware
                    corporation  ("Parent"),  nor MI  Acquisition  Sub,  Inc., a
                    Delaware   corporation   ("Merger   Subsidiary"),   nor  any
                    Affiliates  or  Associates  of Parent  or Merger  Subsidiary
                    shall be deemed to be an  Acquiring  Person by virtue of the
                    execution, delivery or performance of the Agreement and Plan
                    of Merger, entered into as of January 28, 2001, by and among
                    Parent,  Merger  Subsidiary  and the  Company,  as it may be
                    amended  or  supplemented  from  time to time  (the  "Merger
                    Agreement") or the Stock Option  Agreement,  dated as of the
                    date  of  the  Merger  Agreement,  between  Parent  and  the
                    Company,  as the same may be  amended or  supplemented  from
                    time to time (the "Stock Option Agreement"), or by virtue of
                    any of the transactions contemplated by the Merger Agreement
                    or  the   Stock   Option   Agreement,   including,   without
                    limitation,  the  acquisition  by Parent of the  Option  (as
                    defined  in the Stock  Option  Agreement)  or any  shares of
                    Common Stock upon exercise of the Option."

          (b)       Section 1(k) of the Rights  Agreement  is hereby  amended to
                    add the following sentence at the end thereof:

                    "For  purposes  of  Section  3  hereof,  Parent  and  Merger
                    Subsidiary shall each be deemed an Exempt Person."

          2. Amendment of Section 3(a).  Section 3(a) of the Rights Agreement is
hereby amended to add the following sentence at the end thereof:

         "Notwithstanding   anything  in  this  Agreement  to  the  contrary,  a
         Distribution Date shall not be deemed to have occurred by virtue of the
         execution, delivery or performance of the Merger Agreement or the Stock
         Option Agreement or by virtue of any of the  transactions  contemplated
         by the  Merger  Agreement  or the Stock  Option  Agreement,  including,
         without limitation, the acquisition of the Option pursuant to the Stock
         Option  Agreement  or the  acquisition  of shares of Common  Stock upon
         exercise of the Option."

          3.  Amendment  of Section 30.  Section 30 of the Rights  Agreement  is
hereby amended to add the following sentence at the end thereof:

         "Nothing in this Agreement shall be construed to give the holder of any
         Right or any other Person any  additional  legal or  equitable  rights,
         remedies or claims  under this  Agreement  by virtue of the  execution,
         delivery or  performance  of the Merger  Agreement  or the Stock Option
         Agreement or by virtue of any of the  transactions  contemplated by the
         Merger  Agreement or the Stock  Option  Agreement,  including,  without
         limitation,  the acquisition of the Option pursuant to the Stock Option
         Agreement or the acquisition of shares of Common Stock upon exercise of
         the  Option,  including  giving  such  holders the right to acquire any
         securities of Parent, Merger Subsidiary or the Company."

          4.  Effectiveness.  This  Amendment  shall be deemed  effective  as of
January 28, 2001,  as if executed on such date.  Except as amended  hereby,  the
terms and  provisions  of the Rights  Agreement  shall  remain in full force and
effect and shall be otherwise unaffected hereby.

          5. Miscellaneous. This Amendment shall be deemed to be a contract made
under the laws of the State of Delaware and for all  purposes  shall be governed
by and  construed  in  accordance  with the  laws of such  State  applicable  to
contracts to be made and performed  entirely  within such State.  This Amendment
may be executed in any number of counterparts,  each of such counterparts  shall
for all purposes be deemed to be an original,  and all such  counterparts  shall
together  constitute but one and the same  instrument.  If any term,  provision,
covenant  or  restriction  of this  Agreement  is held by a court  of  competent
jurisdiction  or other  authority  to be  invalid,  void or  unenforceable,  the
remainder of the terms, provisions, covenants and restrictions of this Amendment
shall remain in full force and effect and shall in no way be affected,  impaired
or invalidated.


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         Executed as of the date first set forth above.

                                           DALLAS SEMICONDUCTOR CORPORATION,
                                           a Delaware corporation

                                           By: /s/ Chao C. Mai
                                              --------------------------------
                                              Name:    Chao C. Mai
                                              Title:   President

                                           MELLON INVESTOR SERVICES, LLC,
                                           as Rights Agent

                                           By: /s/ Janis Mason
                                              --------------------------------
                                              Name:    Janis Mason
                                              Title:   Relationship Manager