<PAGE>
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
SCHEDULE 14A INFORMATION
Proxy Statement Pursuant to Section 14(a) of the Securities
Exchange Act of 1934 (Amendment No. )
Filed by the Registrant [X]
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
[X] Definitive Additional Materials
[_] Soliciting Material Pursuant to Section 240.14a-11(c) or Section 240.14a-12
INTEGRATED CIRCUIT SYSTEMS
- --------------------------------------------------------------------------------
(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 the appropriate box):
[X] No fee required
[_] Fee computed on table below per Exchange Act Rules 14a-6(i)(4) and 0-11.
(1) Title of each class of securities to which transaction applies:
-------------------------------------------------------------------------
(2) Aggregate number of securities to which transaction applies:
-------------------------------------------------------------------------
(3) Per unit price or other underlying value of transaction computed
pursuant to Exchange Act Rule 0-11 (Set forth the amount on which
the filing fee is calculated and state how it was determined):
-------------------------------------------------------------------------
(4) Proposed maximum aggregate value of transaction:
-------------------------------------------------------------------------
(5) Total fee paid:
-------------------------------------------------------------------------
[_] Fee paid previously with preliminary materials.
[_] Check box if any part of the fee is offset as provided by Exchange
Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee
was paid previously. Identify the previous filing by registration statement
number, or the Form or Schedule and the date of its filing.
(1) Amount Previously Paid:
-------------------------------------------------------------------------
(2) Form, Schedule or Registration Statement No.:
-------------------------------------------------------------------------
(3) Filing Party:
-------------------------------------------------------------------------
(4) Date Filed:
-------------------------------------------------------------------------
Notes:
<PAGE>
[LETTERHEAD OF INTEGRATED CIRCUIT SYSTEMS, INC.]
January 13, 1998
Dear Fellow Shareholder:
As you know, Integrated Circuit Systems' Annual Meeting is now scheduled for
Monday, January 25, 1999. Your support of the ICS management at the Annual
Meeting is very important to the future of the Company. I strongly urge you to
sign, date and return the enclosed WHITE proxy card in support of your
Directors.
In my last letter, I mentioned that Institutional Shareholder Services Inc.
(ISS), the nation's leading independent institutional shareholder advisory firm,
recommended that shareholders vote FOR management's director nominees and
against the dissident slate proposed by Dr. Stavro Prodromou. Since that
letter, Janney Montgomery Scott Inc., the Philadelphia based brokerage, also
issued a report supporting the management of Integrated Circuit Systems.
In its report, Janney Montgomery Scott noted the following* :
. "In our opinion, the appointment of Rudy Gassner as Chairman is a
distinctly positive step and we believe the company has taken
significant strides toward finding a superior CEO to lead the company
forward."
Despite the distractions that a proxy fight poses, the Board of Directors is
focused on the success of ICS and has been working to implement its plan to
increase shareholder value, namely enhancing the core revenue growth rate,
increasing new product introductions, improving ICS' Corporate Governance
structure, improving the Shareholder Communications Program and improving
margins.
We are eager to move past this proxy contest and into a new chapter of success
for ICS. In that regard, and in order to minimize the distractions of a proxy
fight, the Board of Directors chose to avoid courtroom litigation by providing a
shareholder list to Dr. Prodromou, despite his failure to comply with the
requirements of Pennsylvania law. In this way, we will not expend additional
Company time and financial resources on an avoidable courtroom litigation.
*Permission to use quotation was neither sought nor obtained.
<PAGE>
I urge you to vote for management's slate of Directors. Please SIGN, DATE AND
RETURN the enclosed WHITE proxy card in the postage paid envelope provided
today. Even if you have already returned a blue proxy card, you have every
right to change your mind and return a WHITE proxy card in support of your
Directors. Remember, only your latest dated, executed proxy card counts.
Very truly yours,
/s/ Rudolf Gassner
Rudolf Gassner
Chairman of the Board
IF YOUR SHARES ARE HELD IN THE NAME OF A BANK OR BROKER, ONLY THAT ORGANIZATION
CAN VOTE YOUR SHARES. PLEASE DIRECT THE PERSON RESPONSIBLE FOR YOUR ACCOUNT TO
EXECUTE ON YOUR BEHALF A WHITE PROXY CARD WITH A VOTE FOR
YOUR CURRENT MANAGEMENT.
IF YOU HAVE ANY QUESTIONS OR REQUIRE ANY ASSISTANCE, PLEASE CONTACT OUR PROXY
SOLICITOR:
Innisfree M&A Incorporated
Toll Free -- 1-888-750-5834
501 Madison Avenue
20th Floor
New York, NY 10022