United States securities and exchange commission logo

                              August 27, 2020

       Christopher Brown
       General Counsel
       955 Perimeter Road
       Manchester, New Hampshire 03103

                                                        Re: ALLEGRO
                                                            Draft Registration
Statement on Form S-1
                                                            Submitted August 3,
                                                            CIK 0000866291

       Dear Mr. Brown:

              We have reviewed your draft registration statement and have the
following comments. In
       some of our comments, we may ask you to provide us with information so
we may better
       understand your disclosure.

              Please respond to this letter by providing the requested
information and either submitting
       an amended draft registration statement or publicly filing your
registration statement on
       EDGAR. If you do not believe our comments apply to your facts and
circumstances or do not
       believe an amendment is appropriate, please tell us why in your

             After reviewing the information you provide in response to these
comments and your
       amended draft registration statement or filed registration statement, we
may have additional

       Draft Registration Statement on Form S-1 filed August 3, 2020


   1.                                                   Please supplementally
provide us with copies of all written communications, as defined in
                                                        Rule 405 under the
Securities Act, that you, or anyone authorized to do so on your behalf,
                                                        present to potential
investors in reliance on Section 5(d) of the Securities Act, whether or
                                                        not they retain copies
of the communications. Please contact the staff member associated
                                                        with the review of this
filing to discuss how to submit the materials, if any, to us for our
 Christopher Brown
ALLEGROLastNameChristopher Brown
August 27, NameALLEGRO
           2020        MICROSYSTEMS INC
Page 2 27, 2020 Page 2
FirstName LastName
Prospectus Summary
Recent Developments, page 3

2.       Please revise your disclosure to identify Sanken as an affiliate in
this section, including a
         specific statement as to Sanken's percentage of ownership of your
common stock after the
         completion of the initial public offering. We note your disclosure
regarding Sanken and
         OEP on page 12.
Unaudited Pro Forma Consolidated Financial Data
Pro Forma Adjustments, page 68

3.       We note adjustment (E) that appears to reduce your tax provision on a
pro forma basis to
         exclude your $9.5 million settlement with the IRS. We also note on
page F-46 that you
         received a $9.5 million contribution from Sanken to neutralize the
cash impact to the
         company. Please address the following:
             Describe to us the circumstances relating to the contribution from
Sanken, including
             the purpose and timing, and explain how you accounted for the
contribution and how
             it impacted your accounting for the settlement.
             Tell us how you considered the offset you received from Sanken
when concluding to
             adjust your pro forma results for the IRS settlement.
             Tell us how your pro forma adjustment reflecting the IRS
settlement is directly
             attributable to the PSL Divestiture and the transfer of the Sanken
             distribution business to PSL, and has a continuing impact on
Allegro. Refer to Rule
             11-02(b)(6) of Regulation S-X.
Recent Initiatives to Improve Results of Operations, page 71

4.       We note that on April 3, 2020, you amended your agreement relating to
the planned
         purchase of Voxtel, primarily due to the potential impact of
uncertainties from
         the COVID-19 pandemic. Please expand your disclosures here and in the
         Events note to the financial statements to clarify whether the amended
agreement also
         impacted the closing date of the transaction and, if so, to update the
disclosures to indicate
         the date or the period in which you now expect the acquisition to
 Christopher Brown
ALLEGROLastNameChristopher Brown
August 27, NameALLEGRO
           2020        MICROSYSTEMS INC
Page 3 27, 2020 Page 3
FirstName LastName
Key Operating and Financial Metrics
Adjusted EBITDA and Adjusted EBITDA Margin, page 82

5.       We note your adjustment for AMTC Facility consolidation savings of
$14.5 million, and
         that the transition of the facilities began in November 2019 and is
expected to be
         completed by the end of March 2021. Please describe to us in greater
detail what these
         savings represent. For example, tell us whether these are (i) one-time
charges taken in the
         later part of fiscal year 2020 as a result of the transition, (ii)
normal operating expenses
         recorded in the fiscal 2020 that the company does not expect to record
going forward, or
         (iii) your estimate of projected cost savings from the transition.
Explain to us how
         adjusting a non-GAAP measure for these savings is consistent with Item
10(e) of
         Regulation S-K.
6.       In a related matter, please describe to us in greater detail the
nature of the labor cost
         savings reflected in adjustment (j).
Financial Statements
Note 18. Income Taxes, page F-41

7.       We note your disclosures regarding the $9.5 million tax settlement
with the IRS on page
         F-46 and the $5.5 million provision for IRS audit settlement reflected
in the table on page
         F-43. Please explain to us how you accounted for the IRS audit
settlement and how the
         related amounts are reflected in your rate reconciliation on page
F-43. In addition, explain
         to us how you considered the $9.5 million Sanken contribution in
determining your
         income tax provision.
       You may contact Kevin Stertzel at 202-551-3723 or Martin James at
202-551-3671 if you
have questions regarding comments on the financial statements and related
matters. Please
contact Erin Purnell at 202-551-3454 or Geoffrey Kruczek at 202-551-3641 with
any other


                                                                 Division of
Corporation Finance
                                                                 Office of
cc:      Keith L. Halverstam