<PAGE>
 
   As filed with the Securities and Exchange Commission on January 9, 1998

                                               Registration No. 33..............

--------------------------------------------------------------------------------

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                                  ___________

                                   FORM S-8

                            REGISTRATION STATEMENT
                                     Under
                          THE SECURITIES ACT OF 1933
                                   _________

                              SEMTECH CORPORATION
              (Exact name of registrant as specified in charter)

               DELAWARE                                 95-2119684
    (State or other jurisdiction of                     (I.R.S. Employer
    incorporation or organization)                      Identification No.)

                               652 MITCHELL ROAD
                        NEWBURY PARK, CALIFORNIA  91320
                       (Address, including zip code, of
                         principal executive offices)

                                   _________
                      1994 LONG-TERM STOCK INCENTIVE PLAN
                           (Full title of the plan)

                                  JOHN D. POE
                      Chief Executive Officer & President
                              SEMTECH CORPORATION
                               652 Mitchell Road
                        Newbury Park, California  91320
                    (Name and address of agent for service)

  Telephone number, including area code, of agent for service:  (805) 498-2111
                                   _________

                        CALCULATION OF REGISTRATION FEE
                                                                 
<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------------
                                                            Proposed                 Proposed        
                                                             Maximum                  Maximum         
               Title of              Amount to be         Offering Price             Aggregate              Amount of
     Securities to be registered      Registered           Per Share (1)          Offering Price (1)      Registration Fee
----------------------------------------------------------------------------------------------------------------------------
  <S>                                <C>                  <C>                     <C>                     <C>            
  Common Stock, $.01 par value        800,000(2)             $42.375                  $33,900,000             $10,001
----------------------------------------------------------------------------------------------------------------------------
</TABLE>

(1)     Estimated solely for the purpose of calculating the amount of the
        registration fee in accordance with Rule 457 under the Securities Act of
        1933, as amended. The proposed Maximum Aggregate Offering Price is based
        on the last sale price as quoted on NASDAQ National Market System
        January 8, 1998 of $42.375 per share.
(2)     These shares are in addition to those shares previously registered under
        Registrant's 1994 Long-Term Stock Incentive Plan on Form S-8
        Registration Statement (Registration No. 33-85156, Registration No. 
        33-00597 and Registration No. 33-27777).
--------------------------------------------------------------------------------

        This Registration Statement contains ___ sequentially numbered pages.
        The Exhibit Index appears as sequentially numbered page ___.
<PAGE>
 
                                  PART II/1/

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.   INCORPORATION OF DOCUMENTS BY REFERENCE

          The following documents are hereby incorporated into this Registration
Statement and made a part hereof by this reference.

(a)   The Annual Report on Form 10-K of Semtech Corporation (the "Company" or
      "Registrant") for the fiscal year ended January 26, 1997 (file No. 1-6395)
      filed with the Securities Exchange Commission (the "Commission") pursuant
      to the Securities Exchange Act of 1934, as amended (the "Exchange Act");

(b)   The Company's Quarterly Reports on Form 10-Q for the fiscal quarters ended
      April 27, 1997, August 3, 1997 and November 2, 1997, filed with the
      Commission pursuant to the Exchange Act;

(c)   The Company's Proxy Statement for its annual meeting of stockholders held
      on June 5, 1997 (other than the portions thereof identified as not deemed
      filed with the Commission);

(d)   The description of the Company's Common Stock contained in the Company's
      Registration Statement on Form S-2 filed with the Commission on December
      24, 1985, under the Securities Act of 1933, as amended (the "Securities
      Act");

(e)   Registration Statement on Form S-8, filed October 14, 1994, January 31,
      1996 and May 23, 1997 (Registration No. 33-85156, Registration No. 33-
      00597 and Registration No. 33-27777), registering a total of 1,500,000
      shares of the Company's Common Stock, reserved under the 1994 Long-Term
      Stock Incentive Plan, as amended, under the Securities Act; and

          In addition, all Documents filed by the Company with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act subsequent
to the date of this 

_____________________________

1/ Information required by Part I of Form S-8 is contained in a Section 10(a)
-
prospectus to be distributed to each optionee and is omitted from this
Registration Statement in accordance with Rule 428 under the Securities Act and
the Note to Part I of Form S-8.

                                      -2-

<PAGE>
 
Registration Statement, and prior to the filing of a post-effective amendment
which indicates that all securities offered have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement and to be a part hereof from the date
of the filing of such documents with the Commission.


ITEMS 4-7.  DESCRIPTION OF SECURITIES; INTERESTS OF NAMED EXPERTS AND COUNSEL;
            INDEMNIFICATION OF DIRECTORS AND OFFICERS; EXEMPTION FROM
            REGISTRATION CLAIMED.

            Items 4 through 7, inclusive, are omitted in reliance upon General
Instruction E to Form S-8, and the above incorporation by reference of a
previously filed and currently effective Form S-8 (see Item 3, subpart (e)
above) registering securities of the same class under the same plan as those
registered on this Form S-8.


ITEM 8.     EXHIBITS

Exhibit
Number
------

 4.1        1994 Long-Term Stock Incentive Plan, as amended.
 5          Opinion of counsel as to legality of securities being registered.
 23.1       Consent of independent public accountants.
 23.2       Consent of counsel (included in Exhibit 5).
 24.1       Power of Attorney (included herein on the signature page).


ITEM 9.     UNDERTAKINGS.

            Item 9 is omitted in reliance upon General Instruction E to Form S-
8, and the above incorporation by reference of a previously filed and currently
effective Form S-8 (see Item 3, subpart (f) above) registering securities of the
same class under the same plan as those registered on this Form S-8.

                                      -3-
<PAGE>
 
                                  SIGNATURES


          Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Newbury Park, State of California, on January 8, 
1998.


                                       SEMTECH CORPORATION



                                       By: /s/  John D. Poe
                                           ------------------------------------
                                               John D. Poe, President &
                                               Chief Executive Officer

                                      -4-
<PAGE>
 
                               POWER OF ATTORNEY

          KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints John D. Poe, with full power to act as
his true and lawful attorney-in-fact and agent, with full power of substitution
and resubstitution, for him and in his name, place, and stead, in any and all
capacities, to sign any and all amendments (including post-effective amendments)
to this Registration Statement, and to file the same, with all exhibits thereto,
and other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorney-in-fact and agent, full power and
authority to do and perform each and every act and thing requisite and necessary
to be done in connection therewith, as fully to all intents and purposes as he
might or could do in person, hereby ratifying and confirming all that said
attorney-in-fact and agent, or his substitute or substitutes, may lawfully do or
cause to be done by virtue hereof.

          Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
        Signature                                 Title                          Date
        ---------                                 -----                          ----
<S>                                    <C>                                   <C>
/s/ John D. Poe                        President & Chief Executive           January 8, 1998
----------------------------------                                    
(John D. Poe)                          Officer
                                                                             
/s/ David G. Franz, Jr.                Vice President, Chief Financial       January 8, 1998
----------------------------------             
(David G. Franz Jr.)                   Officer & Principal Accounting
                                       Officer 

/s/ James P. Burra                     Director                              January 8, 1998
----------------------------------                                              
(James P. Burra)                                                             

/s/ Rock N. Hankin                     Director                              January 8, 1998
----------------------------------                                              
(Rock N. Hankin)                                                             

/s/ Allen H. Orbuch                    Director                              January 8, 1998
----------------------------------                                              
(Allen H. Orbuch)                                                            

/s/ James T. Schraith                  Director                              January 8, 1998
----------------------------------                                              
(James T. Schraith)                                                          

/s/ Jack O. Vance                      Director                              January 8, 1998
----------------------------------                                              
(Jack O. Vance)                                                                           
</TABLE>

                                      -5-
<PAGE>
 
                                 EXHIBIT INDEX

<TABLE> 
<CAPTION> 
                                                                       Sequentially
Exhibits                                                              Numbered Page
--------                                                              -------------
<S>         <C>                                                       <C> 
4.1         1994 Long-Term Stock Incentive Plan,
            as amended.
         
5           Opinion of counsel as to legality of securities being
            registered.
         
23.1        Consent of independent public accountants.
         
23.2        Consent of counsel (included in Exhibit 5).
         
24.1        Power of Attorney (included herein on the
            signature page).
</TABLE> 

                                      -6-
[{"type": "S-8", "sequence": "1", "description": "REGISTRATION STATEMENT", "secsgml_size_bytes": 12749}]
{"company-data": {"conformed-name": "SEMTECH CORP", "cik": "0000088941", "assigned-sic": "3674", "irs-number": "952119684", "state-of-incorporation": "DE", "fiscal-year-end": "0131"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-44033", "film-number": "98504297"}, "business-address": {"street1": "652 MITCHELL RD", "city": "NEWBURY PARK", "state": "CA", "zip": "91320", "phone": "8054982111"}, "mail-address": {"street2": "652 MITCHELL ROAD", "city": "NEWBURY PARK", "state": "CA", "zip": "91320"}}
As filed with the Securities and Exchange Commission on January 9, 1998

                                               Registration No. 33..............

--------------------------------------------------------------------------------

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                                  ___________

                                   FORM S-8

                            REGISTRATION STATEMENT
                                     Under
                          THE SECURITIES ACT OF 1933
                                   _________

                              SEMTECH CORPORATION
              (Exact name of registrant as specified in charter)

               DELAWARE                                 95-2119684
    (State or other jurisdiction of                     (I.R.S. Employer
    incorporation or organization)                      Identification No.)

                               652 MITCHELL ROAD
                        NEWBURY PARK, CALIFORNIA  91320
                       (Address, including zip code, of
                         principal executive offices)

                                   _________
                      1994 LONG-TERM STOCK INCENTIVE PLAN
                           (Full title of the plan)

                                  JOHN D. POE
                      Chief Executive Officer & President
                              SEMTECH CORPORATION
                               652 Mitchell Road
                        Newbury Park, California  91320
                    (Name and address of agent for service)

  Telephone number, including area code, of agent for service:  (805) 498-2111
                                   _________

                        CALCULATION OF REGISTRATION FEE
----------------------------------------------------------------------------------------------------------------------------
                                                            Proposed                 Proposed        
                                                             Maximum                  Maximum         
               Title of              Amount to be         Offering Price             Aggregate              Amount of
     Securities to be registered      Registered           Per Share (1)          Offering Price (1)      Registration Fee
----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.01 par value        800,000(2)             $42.375                  $33,900,000             $10,001
----------------------------------------------------------------------------------------------------------------------------
(1)     Estimated solely for the purpose of calculating the amount of the
        registration fee in accordance with Rule 457 under the Securities Act of
        1933, as amended. The proposed Maximum Aggregate Offering Price is based
        on the last sale price as quoted on NASDAQ National Market System
        January 8, 1998 of $42.375 per share.
(2)     These shares are in addition to those shares previously registered under
        Registrant's 1994 Long-Term Stock Incentive Plan on Form S-8
        Registration Statement (Registration No. 33-85156, Registration No. 
        33-00597 and Registration No. 33-27777).
--------------------------------------------------------------------------------

        This Registration Statement contains ___ sequentially numbered pages.
        The Exhibit Index appears as sequentially numbered page ___.
PART II/1/

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION OF DOCUMENTS BY REFERENCE

          The following documents are hereby incorporated into this Registration
Statement and made a part hereof by this reference.

(a)   The Annual Report on Form 10-K of Semtech Corporation (the "Company" or
      "Registrant") for the fiscal year ended January 26, 1997 (file No. 1-6395)
      filed with the Securities Exchange Commission (the "Commission") pursuant
      to the Securities Exchange Act of 1934, as amended (the "Exchange Act");

(b)   The Company's Quarterly Reports on Form 10-Q for the fiscal quarters ended
      April 27, 1997, August 3, 1997 and November 2, 1997, filed with the
      Commission pursuant to the Exchange Act;

(c)   The Company's Proxy Statement for its annual meeting of stockholders held
      on June 5, 1997 (other than the portions thereof identified as not deemed
      filed with the Commission);

(d)   The description of the Company's Common Stock contained in the Company's
      Registration Statement on Form S-2 filed with the Commission on December
      24, 1985, under the Securities Act of 1933, as amended (the "Securities
      Act");

(e)   Registration Statement on Form S-8, filed October 14, 1994, January 31,
      1996 and May 23, 1997 (Registration No. 33-85156, Registration No. 33-
      00597 and Registration No. 33-27777), registering a total of 1,500,000
      shares of the Company's Common Stock, reserved under the 1994 Long-Term
      Stock Incentive Plan, as amended, under the Securities Act; and

          In addition, all Documents filed by the Company with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act subsequent
to the date of this 

_____________________________

1/ Information required by Part I of Form S-8 is contained in a Section 10(a)
-
prospectus to be distributed to each optionee and is omitted from this
Registration Statement in accordance with Rule 428 under the Securities Act and
the Note to Part I of Form S-8.

                                      -2-
Registration Statement, and prior to the filing of a post-effective amendment
which indicates that all securities offered have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement and to be a part hereof from the date
of the filing of such documents with the Commission.

ITEMS 4-7.  DESCRIPTION OF SECURITIES; INTERESTS OF NAMED EXPERTS AND COUNSEL;
            INDEMNIFICATION OF DIRECTORS AND OFFICERS; EXEMPTION FROM
            REGISTRATION CLAIMED.

            Items 4 through 7, inclusive, are omitted in reliance upon General
Instruction E to Form S-8, and the above incorporation by reference of a
previously filed and currently effective Form S-8 (see Item 3, subpart (e)
above) registering securities of the same class under the same plan as those
registered on this Form S-8.

ITEM 8.     EXHIBITS

Exhibit
Number
------

 4.1        1994 Long-Term Stock Incentive Plan, as amended.
 5          Opinion of counsel as to legality of securities being registered.
 23.1       Consent of independent public accountants.
 23.2       Consent of counsel (included in Exhibit 5).
 24.1       Power of Attorney (included herein on the signature page).

ITEM 9.     UNDERTAKINGS.

            Item 9 is omitted in reliance upon General Instruction E to Form S-
8, and the above incorporation by reference of a previously filed and currently
effective Form S-8 (see Item 3, subpart (f) above) registering securities of the
same class under the same plan as those registered on this Form S-8.

                                      -3-
SIGNATURES

          Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Newbury Park, State of California, on January 8, 
1998.

                                       SEMTECH CORPORATION

                                       By: /s/  John D. Poe
                                           ------------------------------------
                                               John D. Poe, President &
                                               Chief Executive Officer

                                      -4-
POWER OF ATTORNEY

          KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints John D. Poe, with full power to act as
his true and lawful attorney-in-fact and agent, with full power of substitution
and resubstitution, for him and in his name, place, and stead, in any and all
capacities, to sign any and all amendments (including post-effective amendments)
to this Registration Statement, and to file the same, with all exhibits thereto,
and other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorney-in-fact and agent, full power and
authority to do and perform each and every act and thing requisite and necessary
to be done in connection therewith, as fully to all intents and purposes as he
might or could do in person, hereby ratifying and confirming all that said
attorney-in-fact and agent, or his substitute or substitutes, may lawfully do or
cause to be done by virtue hereof.

          Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.
Signature                                 Title                          Date
        ---------                                 -----                          ----
/s/ John D. Poe                        President & Chief Executive           January 8, 1998
----------------------------------                                    
(John D. Poe)                          Officer
                                                                             
/s/ David G. Franz, Jr.                Vice President, Chief Financial       January 8, 1998
----------------------------------             
(David G. Franz Jr.)                   Officer & Principal Accounting
                                       Officer 

/s/ James P. Burra                     Director                              January 8, 1998
----------------------------------                                              
(James P. Burra)                                                             

/s/ Rock N. Hankin                     Director                              January 8, 1998
----------------------------------                                              
(Rock N. Hankin)                                                             

/s/ Allen H. Orbuch                    Director                              January 8, 1998
----------------------------------                                              
(Allen H. Orbuch)                                                            

/s/ James T. Schraith                  Director                              January 8, 1998
----------------------------------                                              
(James T. Schraith)                                                          

/s/ Jack O. Vance                      Director                              January 8, 1998
----------------------------------                                              
(Jack O. Vance)
-5-
EXHIBIT INDEX
Sequentially
Exhibits                                                              Numbered Page
--------                                                              -------------
4.1         1994 Long-Term Stock Incentive Plan,
            as amended.
         
5           Opinion of counsel as to legality of securities being
            registered.
         
23.1        Consent of independent public accountants.
         
23.2        Consent of counsel (included in Exhibit 5).
         
24.1        Power of Attorney (included herein on the
            signature page).
-6-