United States securities and exchange commission logo

                             January 28, 2021

       Ravi Vig
       Chief Executive Officer
       Allegro Microsystems, Inc.
       955 Perimeter Road
       Manchester, New Hampshire 03103

                                                        Re: Allegro
Microsystems, Inc.
                                                            Draft Registration
Statement on Form S-1
                                                            Submitted January
25, 2021
                                                            CIK No. 0000866291

       Dear Mr. Vig:

                                                        This is to advise you
that we do not intend to review your registration statement.

               We request that you publicly file your registration statement no
later than 48 hours prior
       to the requested effective date and time. Please refer to Rules 460 and
461 regarding requests for
       acceleration. We remind you that the company and its management are
responsible for the
       accuracy and adequacy of their disclosures, notwithstanding any review,
comments, action or
       absence of action by the staff.

                                                        Please contact Thomas
Jones at 202-551-3602 with any questions.


                             Division of Corporation Finance

                             Office of Manufacturing
       cc:                                              Peter M. Labonski, Esq.