SiTime (SITM) DEFA14A Additional proxy soliciting materials

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(RULE 14a-101)

INFORMATION REQUIRED IN

PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No.    )

Filed by the Registrant  ☒

Filed by a Party other than the Registrant  ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material Pursuant to §240.14a-12

SiTime Corporation

(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

☒ No fee required.

☐ Fee paid previously with preliminary materials.

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

Online Go to www.investorvote.com/SITM or scan the QR code — login details are located in the shaded bar below. Votes submitted electronically must be received by 11:59pm, PT on June 1, 2022 Annual Stockholder Meeting Notice Important Notice Regarding the Availability of Proxy Materials for the Si Time Corporation Stockholder Meeting to be Held on June 2, 2022. Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual stockholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on and location of the annual meeting are on the reverse side. Your vote is important! This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. Our Proxy Statement for our 2022 Annual Meeting of Stockholders, along with the proxy card, and our Annual Report to Stockholders for the year ended December 31, 2021 are available at: www.investorvote.com/SITM Easy Online Access — View your proxy materials and vote. Step 1: Go to www.investorvote.com/SITM. Step 2: Click on the icon on the right to view meeting materials. Step 3: Return to the investorvote.com window and follow the instructions on the screen to log in. Step 4: Make your selections as instructed on each screen for your delivery preferences. Step 5: Vote your shares. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. Obtaining a Copy of the Proxy Materials – If you want to receive a copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. Please make your request as instructed on the reverse side on or before May 21, 2022 to facilitate timely delivery. 2NOT

Annual Stockholder Meeting Notice The 2022 Annual Meeting of Stockholders of Si Time Corporation will be held on June 2, 2022 at 9:00am PT, virtually via the internet at meetnow.global/MKKF9SJ. To access the virtual meeting, you must have the information that is printed in the shaded bar located on the reverse side of this form. Proposals to be voted on at the meeting are listed below along with the Board of Directors’ recommendations. The Board of Directors recommend a vote FOR all the nominees listed, FOR Proposals 2 and 4, and for 1 YEAR on Proposal 3: 1. Election of Directors: 01—Raman K. Chitkara 02—Katherine E. Schuelke 03—Rajesh Vashist 2. To approve, on an advisory basis, the compensation of Si Time’s named executive officers as disclosed in Si Time’s proxy statement. 3. To indicate, on an advisory basis, the preferred frequency of stockholder advisory votes on the compensation of SiTime’s named executive officers. 4. To ratify the appointment of BDO USA, LLP as SiTime’s independent registered public accounting firm for the fiscal year ending December 31, 2022. PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your shares you must go online or request a paper copy of the proxy materials to receive a proxy card. Here’s how to order a copy of the proxy materials and select delivery preferences: Current and future delivery requests can be submitted using the options below. If you request an email copy, you will receive an email with a link to the current meeting materials. PLEASE NOTE: You must use the number in the shaded bar on the reverse side when requesting a copy of the proxy materials. — Internet – Go to www.investorvote.com/SITM. — Phone – Call us free of charge at 1-866-641-4276. — Email – Send an email to investorvote@computershare.com with “Proxy Materials SiTime Corporation” in the subject line. Include your full name and address, plus the number located in the shaded bar on the reverse side, and state that you want a paper copy of the meeting materials. To facilitate timely delivery, requests for a paper copy of proxy materials must be received by May 21, 2022.