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                                                                    EXHIBIT 99.3
                                                                    ------------

                                     FORM

                                      of

                          CERTIFICATE OF DESIGNATIONS

                                      of

                 SERIES A JUNIOR PARTICIPATING PREFERRED STOCK

                                      of

                            DATA TRANSLATION, INC.


                        (Pursuant to Section 151 of the
                       Delaware General Corporation Law)

     Data Translation, Inc., a corporation organized and existing under the
General Corporation Law (the "DGCL") of the State of Delaware (hereinafter
                              ----                                        
called the "Corporation"), hereby certifies that the following resolution was
            -----------                                                      
adopted by the Board of Directors of the Corporation as required by Section 151
of the DGCL at a meeting duly called and held on April 14, 1999:


RESOLVED:      That pursuant to Section 4 of Article IV of the Certificate of
--------       Incorporation, as amended, of the Corporation, the Board of
               Directors hereby establishes a series of Preferred Stock, par
               value $0.01 per share (the "Series A Preferred Stock"), of the
                                           ------------------------          
               Corporation and hereby states the designation and number of
               shares, and fixes the preferences, voting powers, qualifications
               and special or relative rights or privileges thereof, as
               follows:


     Series A Junior Participating Preferred Stock:

     Section 1. Designation and Amount. The shares of such series shall be
designated as "Series A Junior Participating Preferred Stock" (the "Series A
                                                                    --------
Preferred Stock") and the number of shares constituting the Series A Preferred
---------------                                                               
Stock shall be 300,000.  Such number of shares may be increased or decreased by
resolution of the Board of Directors; provided that no decrease shall reduce the
                                      --------                                  
number of shares of Series A Preferred Stock to a number less than the number of
shares of Series A Preferred Stock then outstanding, plus the number of shares
                                                     ----                     
reserved for issuance upon the exercise of outstanding options, rights or
warrants or upon conversion of any outstanding securities issued by the
Corporation and convertible into Series A Preferred Stock.
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                                      -2-


          Section 2. Dividends and Distributions.

          (A)  Subject to the rights of the holders of any shares of any series
     of Preferred Stock (or any similar stock) ranking prior and superior to the
     Series A Preferred Stock with respect to dividends, the holders of shares
     of Series A Preferred Stock, in preference to the holders of the Common
     Stock of the Corporation, par value $0.01 per share ("Common Stock"), and
                                                           ------------       
     of any other junior stock, shall be entitled to receive, when, as and if
     declared by the Board of Directors out of funds legally available for the
     purpose, quarterly dividends payable in cash on the first day of March,
     June, September and December in each year (each such date being referred to
     herein as a "Quarterly Dividend Payment Date"), commencing on the first
                  -------------------------------                           
     Quarterly Dividend Payment Date after the first issuance of a share or
     fraction of a share of Series A Preferred Stock, in an amount per share
     (rounded to the nearest cent) equal to the greater of (a) $1 or (b) subject
     to the provision for adjustment hereinafter set forth, 100 times the
     aggregate per share amount of all cash dividends, and 100 times the
     aggregate per share amount (payable in kind) of all non-cash dividends or
     other distributions, other than a dividend payable in shares of Common
     Stock or a subdivision of the outstanding shares of Common Stock (by
     reclassification or otherwise), declared on the Common Stock since the
     immediately preceding Quarterly Dividend Payment Date or, with respect to
     the first Quarterly Dividend Payment Date, since the first issuance of any
     share or fraction of a share of Series A Preferred Stock. In the event the
     Corporation shall at any time declare or pay any dividend on the Common
     Stock payable in shares of Common Stock, or effect a subdivision or
     combination or consolidation of the outstanding shares of Common Stock (by
     reclassification or otherwise than by payment of a dividend in shares of
     Common Stock) into a greater or lesser number of shares of Common Stock,
     then in each such case the amount to which holders of shares of Series A
     Preferred Stock were entitled immediately prior to such event under clause
     (b) of the preceding sentence shall be adjusted by multiplying such amount
     by a fraction, the numerator of which is the number of shares of Common
     Stock outstanding immediately after such event and the denominator of which
     is the number of shares of Common Stock that were outstanding immediately
     prior to such event.

          (B)  The Corporation shall declare a dividend or distribution on the
     Series A Preferred Stock as provided in paragraph (A) of this Section
     immediately after it declares a dividend or distribution on the Common
     Stock (other than a dividend payable in shares of Common Stock); provided
     that, in the event no dividend or distribution shall have been declared on
     the Common Stock during the period between any Quarterly Dividend Payment
     Date and the next subsequent Quarterly Dividend Payment Date, a dividend of
     $1 per share on the Series A Preferred Stock shall nevertheless be payable
     on such subsequent Quarterly Dividend Payment Date.

          (C)  Dividends shall begin to accrue and be cumulative on outstanding
     shares of Series A Preferred Stock from the Quarterly Dividend Payment Date
     next preceding the date of issue of such shares, unless the date of issue 
     of such 
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                                      -3-

     shares is prior to the record date for the first Quarterly Dividend Payment
     Date, in which case dividends on such shares shall begin to accrue from the
     date of issue of such shares, or unless the date of issue is a Quarterly
     Dividend Payment Date or is a date after the record date for the
     determination of holders of shares of Series A Preferred Stock entitled to
     receive a quarterly dividend and before such Quarterly Dividend Payment
     Date, in either of which events such dividends shall begin to accrue and be
     cumulative from such Quarterly Dividend Payment Date. Accrued but unpaid
     dividends shall not bear interest. Dividends paid on the shares of Series A
     Preferred Stock in an amount less than the total amount of such dividends
     at the time accrued and payable on such shares shall be allocated pro rata
     on a share-by-share basis among all such shares at the time outstanding.
     The Board of Directors may fix a record date for the determination of
     holders of shares of Series A Preferred Stock entitled to receive payment
     of a dividend or distribution declared thereon, which record date shall be
     not more than 60 days prior to the date fixed for the payment thereof.

     Section 3. Voting Rights. The holders of shares of Series A Preferred Stock
shall have the following voting rights:

          (A)  Subject to the provision for adjustment hereinafter set forth,
     each share of Series A Preferred Stock shall entitle the holder thereof to
     100 votes on all matters submitted to a vote of the stockholders of the
     Corporation.  In the event the Corporation shall at any time declare or pay
     any dividend on the Common stock payable in shares of Common Stock, or
     effect a subdivision or combination or consolidation of the outstanding
     shares of Common Stock (by reclassification or otherwise than by payment of
     a dividend in shares of Common Stock) into a greater or lesser number of
     shares of Common Stock, then in each such case the number of votes per
     share to which holders of shares of Series A Preferred Stock were entitled
     immediately prior to such event shall be adjusted by multiplying such
     number by a fraction, the numerator of which is the number of shares of
     Common Stock outstanding immediately after such event and the denominator
     of which is the number of shares of Common Stock that were outstanding
     immediately prior to such event.

          (B)  Except as otherwise provided herein, in any other Certificate of
     Designations creating a series of Preferred Stock or any similar stock, or
     by law, the holders of shares of Series A Preferred Stock and the holders,
     of shares of Common Stock and any other capital stock of the Corporation
     having general voting rights shall vote together as one class on all
     matters submitted to a vote of stockholders of the Corporation.

          (C)  Except as set forth herein, or as otherwise provided by law,
     holders of Series A Preferred Stock shall have no special voting rights and
     their consent shall not be required (except to the extent they are entitled
     to vote with holders of Common Stock as set forth herein) for taking any
     corporate action.

     Section 4. Certain Restrictions.
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                                      -4-

          (A)  Whenever quarterly dividends or other dividends or distributions
     payable on the Series A Preferred Stock as provided in Section 2 are in
     arrears, thereafter and until all accrued and unpaid dividends and
     distributions, whether or not declared, on shares of Series A Preferred
     Stock outstanding shall have been paid in full, the Corporation shall not:

               (i)    declare or pay dividends, or make any other distributions,
          on any shares of stock ranking junior (either as to dividends or upon
          liquidation, dissolution or winding up) to the Series A Preferred
          Stock;

               (ii)   declare or pay dividends, or make any other distributions,
          on any shares of stock ranking on a parity (either as to dividends or
          upon liquidation, dissolution or winding up) with the Series A
          Preferred Stock, except dividends paid ratably on the Series A
          Preferred Stock and all such parity stock on which dividends are
          payable or in arrears in proportion to the total amounts to which the
          holders of all such shares are then entitled;

               (iii)  redeem or purchase or otherwise acquire for consideration
          shares of any stock ranking junior (either as to dividends or upon
          liquidation, dissolution or winding up) to the Series A Preferred
          Stock, provided that the Corporation may at any time redeem, purchase
          or otherwise acquire shares of any such junior stock in exchange for
          shares of any stock of the Corporation ranking junior (either as to
          dividends or upon dissolution, liquidation or winding up) to the
          Series A Preferred Stock; or

               (iv)   redeem or purchase or otherwise acquire for consideration
          any shares of Series A Preferred Stock, or any shares of stock ranking
          on a parity with the Series A Preferred Stock, except in accordance
          with a purchase offer made in writing or by publication (as determined
          by the Board of Directors) to all holders of such shares upon such
          terms as the Board of Directors, after consideration of the respective
          annual dividend rates and other relative rights and preferences of the
          respective series and classes, shall determine in good faith will
          result in fair and equitable treatment among the respective series or
          classes.

          (B)  The Corporation shall not permit any subsidiary of the
     Corporation to purchase or otherwise acquire for consideration any shares
     of stock of the Corporation unless the Corporation could, under paragraph
     (A) of this Section 4, purchase or otherwise acquire such shares at such
     time and in such manner.

     Section 5. Reacquired Shares. Any shares of Series A Preferred Stock
purchased or otherwise acquired by the Corporation in any manner whatsoever
shall be retired and canceled promptly after the acquisition thereof. All such
shares shall upon their cancellation become authorized but unissued shares of
Preferred Stock and may be reissued as part of a new series of Preferred Stock
subject to the conditions and restrictions on issuance set forth herein, in the
Certificate of Incorporation, or in any 
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                                      -5-

other Certificate of Designations creating a series of Preferred Stock or any
similar stock or as otherwise required by law.

     Section 6. Liquidation, Dissolution or Winding Up. Upon any liquidation,
dissolution or winding up of the Corporation, no distribution shall be made (1)
to the holders of shares of stock ranking junior (either as to dividends or upon
liquidation, dissolution or winding up) to the Series A Preferred Stock unless,
prior thereto, the holders of shares of Series A Preferred Stock shall have
received $100 per share, plus an amount equal to accrued and unpaid dividends
and distributions thereon, whether or not declared, to the date of such payment,
provided that the holders of shares of Series A Preferred Stock shall be
entitled to receive an aggregate amount per share, subject to the provision for
adjustment hereinafter set forth, equal to 100 times the aggregate amount to be
distributed per share to holders of shares of Common Stock, or (2) to the
holders of shares of stock ranking on a parity (either as to dividends or upon
liquidation, dissolution or winding up) with the Series A Preferred Stock,
except distributions made ratably on the Series A Preferred Stock and all such
parity stock in proportion to the total amounts to which the holders of all such
shares are entitled upon such liquidation, dissolution or winding up. In the
event the Corporation shall at any time declare or pay any dividend on the
Common Stock payable in shares of Common Stock, or effect a subdivision or
combination or consolidation of the outstanding shares of Common Stock (by
reclassification or otherwise than by payment of a dividend in shares of Common
Stock) into a greater or lesser number of shares of Common Stock, then in each
such case the aggregate amount to which holders of shares of Series A Preferred
Stock were entitled immediately prior to such event under the proviso in clause
(1) of the preceding sentence shall be adjusted by multiplying such amount by a
fraction the numerator of which is the number of shares of Common Stock
outstanding immediately after such event and the denominator of which is the
number of shares of Common Stock that were outstanding immediately prior to such
event.

     Section 7. Consolidation, Merger, etc. In case the Corporation shall enter
into any consolidation, merger, combination or other transaction in which the
shares of Common Stock are exchanged for or changed into other stock or
securities, cash and/or any other property, then in any such case each share of
Series A Preferred Stock shall at the same time be similarly exchanged or
changed into an amount per share, subject to the provision for adjustment
hereinafter set forth, equal to 100 times the aggregate amount of stock
securities, cash and/or any other property (payable in kind), as the case may
be, into which or for which each share of Common Stock is changed or exchanged.
In the event the Corporation shall at any time declare or pay any dividend on
the Common Stock payable in shares of Common Stock, or effect a subdivision or
combination or consolidation of the outstanding shares of Common Stock (by
reclassification or otherwise than by payment of a dividend in shares of Common
Stock) into a greater or lesser number of shares of Common Stock, then in each
such case the amount set forth in the preceding sentence with respect to the
exchange or change of shares of Series A Preferred Stock shall be adjusted by
multiplying such amount by a fraction, the numerator of which is the number of
shares of Common Stock outstanding immediately after such event and the
denominator of which is the 
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                                      -6-

number of shares of Common Stock that were outstanding immediately prior to such
event.

     Section 8. No Redemption. The shares of Series A Preferred Stock shall not
be redeemable.

     Section 9. Rank. The Series A Preferred Stock shall rank, with respect to
the payment of dividends and the distribution of assets, junior to all series of
any other class of the Corporation's Preferred Stock.

     Section 10. Amendment. The Certificate of Incorporation of the Corporation
shall not be amended in any manner which would materially alter or change the
powers, preferences or special rights of the Series A Preferred Stock so as to
affect them adversely without the affirmative vote of the holders of at least
two-thirds of the outstanding shares of Series A Preferred Stock, voting
together as a single class.

     IN WITNESS WHEREOF, this Certificate of Designations is executed on behalf
of the Corporation by its Chief Executive Officer and attested by its Secretary
as of April __, 1999.


ATTEST:

                                    By: __________________________
                                    Name: Ellen W. Harpin
                                    Title: Secretary