<PAGE>

                                                                   EXHIBIT 10.27
                                                                   -------------

                          FORM OF EMPLOYMENT AGREEMENT
                          ----------------------------


     This EMPLOYMENT AGREEMENT (this "Agreement"), entered into as of March 1,
                                      ---------
1998, by and between BENCHMARQ Microelectronics, Inc., a Delaware corporation
(the "Company"), and ___________ (the "Executive"), evidences that;
      -------                          ---------

     WHEREAS, the Executive is a senior executive of the Company and has made
and/or is expected to make or continue to make significant contributions to the
profitability, growth and financial strength of the Company;

     WHEREAS, the Company, Unitrode Corporation, a Maryland corporation

("Unitrode"), and Merrimack Corporation, a Delaware corporation and a wholly-
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owned subsidiary of Unitrode ("Newco"), have entered into an Agreement and Plan
                               -----
of Merger pursuant to which Newco will be merged (the "Merger") with and into
                                                       ------
the Company;

     WHEREAS, the Company desires to establish certain minimum compensation
rights with respect to the key senior executives of the Company, including the
Executive, applicable in the event that the Merger is consummated; and

     WHEREAS, the Executive is willing to render services to the Company on the
terms and subject to the conditions set forth in this Agreement;

     NOW, THEREFORE, the Company and the Executive agree as follows:

     1.   TERM OF AGREEMENT:  The period during which this Agreement shall be in
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effect (the "Term") shall commence as of the consummation of the Merger and
             ----
shall continue thereafter for a period of one (1) year.

     2.   EMPLOYMENT:  Upon the consummation of the Merger, this Agreement shall
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become effective and the Company shall continue the Executive in its employ and
the Executive shall remain in the employ of the Company for the Term, in the
positions and with substantially the same duties and responsibilities that the
Executive had immediately prior to the consummation of the Merger.  Throughout
the Term, the Executive shall devote substantially all of the Executive's time
during normal business hours (subject to vacations, sick leave and other
absences in accordance with the policies of the Company as from time to time in
effect for senior executives) to the business and affairs of the Company.

     3.   COMPENSATION DURING THE TERM:
          ----------------------------

          (a)  During the Term, the Company covenants that the Executive shall
               receive from the Company (i) annual base salary at a rate not
               less than one hundred percent (100%) of the Executive's annual
               fixed or
<PAGE>

               base compensation from the Company prior to the consummation of
               the Merger or such higher rate as may be determined from time to
               time by the Board of Directors of the Company (the "Board")
                                                                   -----
               (which base salary at such rate is herein referred to as "Base
                                                                         ----
               Pay").  The Base Pay shall be payable twice monthly, on the 15th
               ---
               day and on the last day of each calendar month during the Term,
               in equal installments or in such other regular installments as
               the Company may pay its employees from time to time.

          (b)  For the Executive's service pursuant to Section 2 hereof, during
                                                       ---------
               the Term the Executive shall, be a full participant in, and shall
               be entitled to the perquisites, benefits and service credit for
               benefits as provided under any and all employee retirement income
               and welfare benefit policies, plans, programs or arrangements in
               which senior executives of the Company participate generally,
               including without limitation any stock option, stock purchase,
               stock appreciation, savings, pension, supplemental executive
               retirement or other retirement income or welfare benefit,
               deferred compensation, incentive compensation, group and/or
               executive life, accident, health, dental, medical/hospital or
               other insurance (whether funded by actual insurance or self-
               insured by the Company), disability, salary continuation, expense
               reimbursement and other employee benefit policies, plans,
               programs or arrangements of the Company that may from time to
               time exist (collectively, "Employee Benefits"); provided,
                                          -----------------
               however, that the Executive's rights thereunder shall be governed
               by the terms thereof and shall not be enlarged or diminished
               hereunder or otherwise affected hereby.  Travel and other
               expenses incurred by the Executive on behalf of the Company shall
               be reimbursed in accordance with the Company's policies on such
               reimbursements as in effect from time to time.

          (c)  In addition to the Base Pay, the Executive shall be eligible to
               receive an annual cash bonus in accordance with the terms of the
               Company's bonus plan in effect from time to time.

     4.   TERMINATION:
          -----------

          (a)  The Company may terminate the employment of the Executive
               hereunder at any time for Just Cause (as hereinafter defined),
               such termination to be communicated by the Company to the
               Executive by written notice.  The Executive may terminate his own
               employment hereunder at any time without Good Reason (as
               hereinafter defined), such termination to be communicated by the
               Executive to the Company by written notice.  For the purposes
               hereof, "Just Cause" means a determination by the Board, in the
                        ----------
               exercise of its reasonable judgment, that any of the following
               has occurred:
<PAGE>

                (i) the willful and continued failure by the Executive to
                    perform his duties and responsibilities with the Company
                    under this Agreement (other than any such failure resulting
                    from his incapacity due to physical or mental illness or
                    disability) which is not cured to the Company's satisfaction
                    within 15 days after notice to the Executive by the Board;

               (ii) excessive absenteeism by the Executive unrelated to ill
                    health, physical disability or mental disability which is
                    not cured to the Company's reasonable satisfaction within 15
                    days after notice to the Executive by the Board;

              (iii) the engaging by the Executive in any act which is intended
                    to be, and is, materially injurious to the Company,
                    financially or otherwise which is not cured (if curable) to
                    the Company's reasonable satisfaction within 15 days after
                    notice to the Executive by the Board;

               (iv) the conviction of the Executive of a criminal offense
                    involving fraud, dishonesty or other moral turpitude;

                (v) material breach of this Agreement by the Executive; or

               (vi) the engaging by the Executive in any intentional act or acts
                    of dishonesty resulting or intended to result directly or
                    indirectly in personal gain to the Executive at the
                    Company's expense (other than acts which have an
                    insignificant impact upon the Company).

          (b)  Upon the termination of the Executive's employment by the Company
               for Just Cause or by the Executive without Good Reason, the
               Executive shall not be entitled to any severance, termination or
               other compensation payment other than compensation earned by the
               Executive before the date of termination of employment calculated
               per diem up to and including the date of termination, together
               with any amount to which the Executive may be entitled under the
               provisions of applicable employment legislation in force at the
               date of termination of the Executive's employment.

     5.   TERMINATION WITHOUT JUST CAUSE OR FOR GOOD REASON:
          -------------------------------------------------

          (a)  The Company may terminate the employment of the Executive
               hereunder at any time without Just Cause, such termination to be
               communicated by the Company to the Executive by written notice.
               In addition, the Executive may terminate his employment for Good
               Reason, such termination to be communicated by the Executive to
               the Company by written notice.  For purposes of this Agreement,
<PAGE>

               "Good Reason" shall mean (i) a substantial adverse alteration in
                -----------
               the nature or status of the Executive's responsibilities with the
               Company, (ii) a change in the regular place of work of the
               Executive to a location more than 50 miles from that in effect as
               of the consummation of the Merger, (iii) any purported
               termination of the Executive's employment which is not effected
               in accordance with this Agreement (which purported termination
               shall not be effective) or (iv) the failure of the Company to
               obtain a satisfactory agreement from any successor to assume and
               agree to perform this Agreement.  The Executive's right to
               terminate his employment for Good Reason shall not be affected by
               his incapacity due to ill health or physical or mental
               disability.  The Executive's continued employment shall not
               constitute consent to, or a waiver of rights with respect to, any
               circumstance constituting Good Reason hereunder.

          (b)  Upon the termination of the Executive's employment without Just
               Cause or for Good Reason, the Company shall have the following
               obligations:

               (i)  if not theretofore paid, the Company shall pay to or to the
                    order of the Executive within 10 days after the date of
                    termination of the Executive's employment hereunder the
                    fraction of the Base Pay then in effect hereunder earned by
                    or payable to the Executive hereunder from the beginning of
                    the Term to the date of termination (less any deductions
                    required by law);

               (ii) the Company shall pay to or to the order of the Executive
                    within 10 days after the date of termination of the
                    Executive's employment hereunder, a lump sum equal to the
                    aggregate annual Base Pay then in effect (less any
                    deductions required by law); and

              (iii) the Company shall pay to the Executive all outstanding and
                    accrued regular and special vacation pay, if any, to the
                    date of termination.

          (c)  During the Term and for a period of one (1) year after the
          termination of this Agreement, the Executive will not hire, entice or
          in any other manner persuade or attempt to persuade any employee,
          independent contractor,licensee, licensor, dealer, supplier, client or
          customer of the Company or any of its subsidiaries to discontinue its
          relationship or violate any agreement with the Company or any of its
          subsidiaries as an employee, independent contractor, licensee,
          licensor, dealer, supplier, client or customer, respectively.
<PAGE>

     6.   TERMINATION UPON DEATH OR DISABILITY:
          ------------------------------------

          (a)  The Company may terminate the employment of the Executive
               hereunder at any time forthwith upon the death or permanent
               disability of the Executive, such termination to be communicated
               by written notice given by the Company to the Executive or, in
               the event of the death of the Executive, to his personal
               representative or his estate.  The Executive shall be considered
               to have become permanently disabled if (i) in any period of 12
               consecutive months during the Term, because of ill health or
               physical or mental disability or for other causes beyond the
               control of the Executive, the Executive has been or is reasonably
               likely to be continuously unable or unwilling or has failed to
               perform his duties and responsibilities hereunder for 120
               consecutive days or (ii) during any period of 12 consecutive
               months during the Term, the Executive has been unable or
               unwilling or has failed to perform his duties and
               responsibilities hereunder for a total of 180 days, consecutive
               or not.

          (b)  On termination of the Executive's employment as a result of the
               Executive's death or as a result of the Executive having become
               permanently disabled, the Company shall pay to the Executive or
               his personal representative on behalf of the estate of the
               Executive, within 10 days after the date of termination of the
               Executive's employment, the fraction of the Base Pay then in
               effect hereunder and not otherwise paid by the Company to the
               Executive as of the date of termination (less any disability
               insurance payments made for periods through the date of
               termination and any deductions required by law).

     7.   RETURN OF PROPERTY.  Upon the termination of the employment of the
          ------------------
Executive hereunder, regardless of the reason therefor, the Executive will
immediately deliver or cause to be delivered to the Company all books,
documents, effects, money, securities or other property (including manuals,
computer disks and software products) belonging to the Company, or for which the
Company is liable to others, which are in the possession, charge or custody of
the Executive.  The Executive agrees not to make for personal or business use or
for the use of any other party any reproductions or copies of any such books,
documents, effects or other property belonging to the Company or for which the
Company is liable to others.

     8.   MISCELLANEOUS:
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          (a)  A termination of the Executive's employment hereunder shall not
               affect any rights which the Executive may have pursuant to any
               agreement, policy, plan, program or arrangement of the Company
               providing Employee Benefits, which rights shall be governed by
               the terms thereof.  Without limiting the generality of the
               foregoing, upon the termination of the Executive's employment,
               the Company shall
<PAGE>

               (upon request of the Executive) pay over to the Executive all
               vested benefits to which the Executive is entitled under and in
               accordance with the terms of the employee savings, stock
               ownership, supplemental executive retirement and similar plans of
               the Company in the event such payments are not otherwise made in
               accordance with the terms of such plans.

          (b)  There shall be no right of set-off or counterclaim in respect of
               any claim, debt or obligation against any payment to or benefit
               (including Employee Benefits) of the Executive provided for in
               this Agreement.

          (c)  Without limiting the rights of the Executive at law or in equity,
               if the Company fails to make any payment required to be made
               hereunder on a timely basis, the Company shall pay interest on
               the amount thereof at an annualized rate of interest equal to the
               highest rate allowed by applicable usury laws.

     9.   NO MITIGATION OBLIGATION:  The Company hereby acknowledges that it
          ------------------------
will be difficult, and may be impossible, for the Executive to find reasonably
comparable employment following the termination of the Executive's employment.
Accordingly, the parties hereto expressly agree that the payment of the
severance compensation by the Company to the Executive in accordance with the
terms of this Agreement will be liquidated damages, and that the Executive shall
not be required to mitigate the amount of any payment provided for in this
Agreement by seeking other employment or otherwise, nor shall any profits,
income, earnings or other benefits from any source whatsoever create any
mitigation, offset, reduction or any other obligation on the part of the
Executive hereunder or otherwise.

     10.  LEGAL FEES AND EXPENSES: It is the intent of the Company that the
          -----------------------
Executive not be required to incur the expenses associated with the enforcement
of the Executive's rights under this Agreement by litigation or other legal
action because the cost and expense thereof would substantially detract from the
benefits intended to be extended to the Executive hereunder.  Accordingly, if it
should appear to the Executive that the Company has failed to comply with any of
its obligations under this Agreement or in the event that the Company or any
other person takes any action to declare this Agreement void or unenforceable,
or institutes any litigation designed to deny, or to recover from, the Executive
the benefits intended to be provided to the Executive hereunder, the Company
irrevocably authorizes the Executive from time to time to retain counsel of the
Executive's choice, at the expense of the Company as hereafter provided, to
represent the Executive in connection with the litigation or defense of any
litigation or other legal action, whether by or against the Company or any
director, officer, shareholder or other person affiliated with the Company, in
any jurisdiction.  Notwithstanding any existing or prior attorney-client
relationship between the Company and such counsel, the Company irrevocably
consents to the Executive's entering into an attorney-client relationship with
such counsel (other than Winstead Sechrest & Minick P.C.), and in that
connection the Company and the Executive agree that a confidential relationship
shall exist between the Executive and such counsel.  The Company shall
<PAGE>

pay or cause to be paid and shall be solely responsible for any and all
attorneys' and related fees and expenses incurred by the Executive as a result
of the Company's failure to perform this Agreement or any provision thereof or
as a result of the Company or any person contesting the validity or
enforceability of this Agreement or any provision thereof as aforesaid.

     11.  EMPLOYMENT RIGHTS:  Nothing expressed or implied in this Agreement
          -----------------
shall create any right or duty on the part of the Company (on the one hand) or
the Executive (on the other hand) to have the Executive remain in the employment
of the Company prior to the consummation of the Merger.

     12.  WITHHOLDING OF TAXES:  The Company may withhold from any amounts
          --------------------
payable under this Agreement all federal, state, city or other taxes as shall be
required pursuant to any law or government regulation or ruling.

     13.  SUCCESSORS AND BINDING AGREEMENT:
          --------------------------------

          (a)  This Agreement shall not be assignable, transferable or delegable
               by the Company.

          (b)  This Agreement shall inure to the benefit of and be enforceable
               by the Executive's personal or legal representatives, executors,
               administrators, successors, heirs, distributees and/or legatees.

          (c)  This Agreement is personal in nature and neither of the parties
               hereto shall, without the consent of the other, assign, transfer
               or delegate this Agreement or any rights or obligations
               hereunder.  Without limiting the generality of the foregoing, the
               Executive's right to receive payments hereunder shall not be
               assignable, transferable or delegable, whether by pledge,
               creation of a security interest or otherwise, other than by a
               transfer by the Executive's will or by the laws of descent and
               distribution and, in the event of any attempted assignment or
               transfer contrary to this Subsection 13(c), the Company shall
                                         ----------------
               have no liability to pay any amount so attempted to be assigned,
               transferred or delegated.

          (d)  The Company and the Executive recognize that each Party will have
               no adequate remedy at law for breach by the other of any of the
               agreements contained herein and, in the event of any such breach,
               the Company and the Executive hereby agree and consent that the
               other shall be entitled to a decree of specific performance,
               mandamus or other appropriate remedy to enforce performance of
               this Agreement.

     14.  APPLICABLE LAW.   THIS AGREEMENT WILL BE GOVERNED BY AND CONSTRUED IN
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ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS (EXCLUSIVE OF CONFLICTS OF LAW
PRINCIPLES) AND THE LAWS OF THE
<PAGE>

UNITED STATES OF AMERICA AND WILL, TO THE MAXIMUM EXTENT PRACTICABLE, BE DEEMED
TO CALL FOR PERFORMANCE IN DALLAS COUNTY, TEXAS.  COURTS WITHIN THE STATE OF
TEXAS WILL HAVE JURISDICTION OVER ANY AND ALL DISPUTES BETWEEN THE PARTIES
HERETO, WHETHER IN LAW OR EQUITY, ARISING OUT OF OR RELATING TO THIS AGREEMENT.
THE PARTIES CONSENT TO AND AGREE TO SUBMIT TO THE JURISDICTION OF SUCH COURTS.
VENUE IN ANY SUCH DISPUTE, WHETHER IN FEDERAL OR STATE COURT, WILL BE LAID IN
DALLAS COUNTY, TEXAS. EACH OF THE PARTIES HEREBY WAIVES, AND AGREES NOT TO
ASSERT IN ANY SUCH DISPUTE, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW,
ANY CLAIM THAT (I) SUCH PARTY IS NOT PERSONALLY SUBJECT TO THE JURISDICTION OF
SUCH COURTS, (II) SUCH PARTY AND SUCH PARTY'S PROPERTY IS IMMUNE FROM ANY LEGAL
PROCESS ISSUED BY SUCH COURTS OR (III) ANY LITIGATION COMMENCED IN SUCH COURTS
IS BROUGHT IN AN INCONVENIENT FORUM.

     15.  NOTICES.  All notices, demands, requests or other communications that
          -------
may be or are required to be given, served or sent by either party to the other
party pursuant to this Agreement will be in writing and will be mailed by first-
class, registered or certified mail, return receipt requested, postage prepaid,
or transmitted by hand delivery, telegram or facsimile transmission addressed as
follows:

          (a)  If to the Company:           BENCHMARQ Microelectronics, Inc.
                                            17919 Waterview Parkway
                                            Dallas, Texas  75252
                                            Facsimile No.:  (972) 437-9198

               with a copy (which will
               not constitute notice)  to:  Winstead Sechrest & Minick P.C.
                                            5400 Renaissance Tower
                                            1201 Elm Street
                                            Dallas, Texas  75270
                                            Facsimile No.: (214) 745-5390
                                            Attn: Robert E. Crawford, Jr., Esq.

          (b)  If to the Executive: ______________________
                                    ______________________
                                    ______________________

Either party may designate by written notice a new address to which any notice,
demand, request or communication may thereafter be given, served or sent.  Each
notice, demand, request or communication that is mailed, delivered or
transmitted in the manner described above will be deemed sufficiently given,
served, sent and received for all purposes at such time as it is delivered to
the addressee with the return receipt, the delivery receipt, the affidavit of
messenger or (with respect to a facsimile transmission) the answer back being
deemed conclusive evidence of such delivery or at such time as delivery is
refused by the addressee upon presentation.
<PAGE>

     16.  GENDER.   Words of any gender used in this Agreement will be held and
          ------
construed to include any other gender, and words in the singular number will be
held to include the plural, unless the context otherwise requires.

     17.  AMENDMENT.  This Agreement may not be amended or supplemented except
          ---------
pursuant to a written instrument signed by the party against whom such amendment
or supplement is to be enforced.  Nothing contained in this Agreement will be
deemed to create any agency, joint venture, partnership or similar relationship
between the parties to this Agreement.  Nothing contained in this Agreement will
be deemed to authorize either party to this Agreement to bind or obligate the
other party.

     18.  COUNTERPARTS.   This Agreement may be executed in multiple
          ------------
counterparts, each of which will be deemed to be an original and all of which
will be deemed to be a single agreement.  This Agreement will be considered
fully executed when all  parties have executed an identical counterpart,
notwithstanding that all signatures may not appear on the same counterpart.

     19.  SEVERABILITY.  If any of the provisions of this Agreement are
          ------------
determined to be invalid or unenforceable, such invalidity or unenforceability
will not invalidate or render unenforceable the remainder of this Agreement, but
rather the entire Agreement will be construed as if not containing the
particular invalid or unenforceable provision or provisions, and the rights and
obligations of the parties will be construed and enforced accordingly.  The
parties acknowledge that if any provision of this Agreement is determined to be
invalid or unenforceable, it is their desire and intention that such provision
be reformed and construed in such manner that it will, to the maximum extent
practicable, be deemed to be valid and enforceable.

     20.  THIRD PARTIES.  Except as expressly set forth or referred to in this
          -------------
Agreement, nothing in this Agreement is intended or will be construed to confer
upon or give to any party other than the parties to this Agreement and their
successors and permitted assigns, if any, any rights or remedies under or by
reason of this Agreement.

     21.  WAIVER.  No failure or delay in exercising any right hereunder will
          ------
operate as a waiver thereof, nor will any single or partial exercise thereof
preclude any other or further exercise or the exercise of any other right.

     22.  PRIOR AGREEMENT.  This Agreement is voluntarily entered into and upon
          ---------------
the consummation of the Merger will supersede and take the place of any prior
severance or employment agreements between the parties hereto.  The parties
hereto expressly agree and hereby declare that any and all prior severance or
employment agreements between the parties are terminated and of no force or
effect.
<PAGE>

     23.  INDEMNITY. UNDER CERTAIN CIRCUMSTANCES, THIS AGREEMENT IMPOSES
          ---------
INDEMNIFICATION OBLIGATIONS ON THE PARTIES HERETO.



             [THE REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK.]
<PAGE>

  IN WITNESS WHEREOF, the parties have caused this Agreement to be duly executed
               and delivered as of the date first above written.


                              COMPANY:
                              --------

                              BENCHMARQ MICROELECTRONICS, INC.


                              By:_________________________________
                                 Name:____________________________
                                 Title:___________________________


                              EXECUTIVE:
                              ----------

                              ____________________________________