Form 425

Filed by ON Semiconductor Corporation

Pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12

of the Securities Exchange Act of 1934

Subject Company: Catalyst Semiconductor, Inc.

This document contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, statements related to the benefits of the proposed transaction between ON Semiconductor Corporation (“ON”) and Catalyst Semiconductor (“Catalyst Semiconductor”) and the future financial performance of ON. These forward-looking statements are based on information available to ON and Catalyst Semiconductor as of the date of this release and current expectations, forecasts and assumptions and involve a number of risks and uncertainties that could cause actual results to differ materially from those anticipated by these forward-looking statements. Such risks and uncertainties include a variety of factors, some of which are beyond ON’s or Catalyst Semiconductor’s control. In particular, such risks and uncertainties include difficulties encountered in integrating merged businesses; the risk that the transaction does not close, including the risk that the requisite stockholder and regulatory approvals may not be obtained; the variable demand and the aggressive pricing environment for semiconductor products; dependence on each company’s ability to successfully manufacture in increasing volumes on a cost-effective basis and with acceptable quality its current products; the adverse impact of competitive product announcements; revenues and operating performance, changes in overall economic conditions, the cyclical nature of the semiconductor industry, changes in demand for our products, changes in inventories at customers and distributors, technological and product development risks, availability of raw materials, competitors’ actions, pricing and gross margin pressures, loss of key customers, order cancellations or reduced bookings, changes in manufacturing yields, control of costs and expenses, significant litigation, risks associated with acquisitions and dispositions, risks associated with leverage and restrictive covenants in debt agreements, risks associated with international operations, the threat or occurrence of international armed conflict and terrorist activities both in the United States and internationally, risks and costs associated with increased and new regulation of corporate governance and disclosure standards (including pursuant to Section 404 of the Sarbanes-Oxley Act of 2002), and risks involving environmental or other governmental regulation. Information concerning additional factors that could cause results to differ materially from those projected in the forward-looking statements is contained in ON’s Annual Report on Form 10-K as filed with the Securities and Exchange Commission (the “SEC”) on February 12, 2008, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and other of ON’s SEC filings, and Catalyst Semiconductor’s Annual Report on Form 10-K as filed with the SEC on July 3, 2008, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and other of Catalyst Semiconductor SEC filings. These forward-looking statements should not be relied upon as representing ON’s or Catalyst Semiconductor’s views as of any subsequent date and neither undertake any obligation to update forward-looking statements to reflect events or circumstances after the date they were made.

This communication is being made in respect of the proposed transaction involving ON and Catalyst Semiconductor. In connection with the proposed transaction, ON plans to file with the SEC a Registration Statement on Form S-4 containing a Proxy Statement of Catalyst Semiconductor and a Prospectus of ON, and each of ON and Catalyst Semiconductor plan to file with the SEC other documents regarding the proposed transaction. The definitive Proxy Statement/Prospectus will be mailed to stockholders of Catalyst Semiconductor. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE PROXY STATEMENT/PROSPECTUS AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION.


Investors and security holders will be able to obtain free copies of the Registration Statement and the Proxy Statement/Prospectus (when available) and other documents filed with the SEC by ON and Catalyst Semiconductor through the web site maintained by the SEC at www.sec.gov. In addition, investors and security holders will be able to obtain free copies of the Registration Statement and the Proxy Statement/Prospectus (when available) and other documents filed with the SEC from ON by directing a request to ON Semiconductor Corporation, 5005 East McDowell Road, Phoenix, AZ, 85008, Attention: Investor Relations (telephone: (602) 244-3437) or going to ON’s corporate website at www.onsemi.com, or from Catalyst Semiconductor by directing a request to Catalyst Semiconductor, Inc., 2975 Stender Way, Santa Clara, CA 95054, Attention: Investor Relations (telephone: (408) 542-1200) or going to Catalyst Semiconductor’s corporate website at www.catsemi.com.

ON and Catalyst Semiconductor and their respective directors and executive officers may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information regarding ON’s directors and executive officers is contained in ON’s annual proxy statement filed with the SEC on April 4, 2008, as supplemented a Current Report on Form 8-K filed with the SEC on March 17, 2008. Information regarding Catalyst Semiconductor’s directors and executive officers is contained in Catalyst Semiconductor’s annual proxy statement filed with the SEC on August 24, 2007. Additional information regarding the interests of such potential participants will be included in the Proxy Statement/Prospectus and the other relevant documents filed with the SEC (when available).

Filed below is a presentation to ON Sales, ON Sales Representatives, ON Marketing, and ON Customer Service Representatives on July 17, 2008 regarding ON’s proposed acquisition of Catalyst.


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ON Semiconductor
Catalyst Semiconductor
Announcement
Outreach Training –
Customer Facing Teams


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Confidential Proprietary
Call Agenda
ON Semiconductor / Catalyst Semiconductor Announcement
Catalyst Semiconductor Overview
Customer Communication
Expectations from Sales and Marketing and Customer Facing
Teams


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Confidential Proprietary
ON Semiconductor to Acquire Catalyst Semiconductor, Inc. in an All-Stock Transaction
PHOENIX,
AZ
and
SANTA
CLARA,
CA
July
17,
2008
ON
Semiconductor
Corporation
(Nasdaq:
ONNN)
and Catalyst Semiconductor, Inc. (Nasdaq: CATS) today announced the signing of a definitive merger
agreement providing for the acquisition of Catalyst Semiconductor by ON Semiconductor in an all-stock
transaction in which Catalyst shareholders will receive 0.706 shares of ON Semiconductor common stock for
each share of Catalyst common stock they own.  This represents an equity value of approximately $115
million and an enterprise value of approximately $85 million.
“The acquisition of Catalyst Semiconductor will add to our high gross margin analog and mixed-signal
product
offerings
for
the
digital
consumer
and
wireless
end-markets,”
said
Keith
Jackson,
ON
Semiconductor
president and CEO.  “Catalyst Semiconductor’s analog and mixed-signal business represented more than
$11
million
in
sales
as
of
their
April
2008
fiscal
year
end
-
a
business
that
grew
more
than
90
percent
versus
the prior year. Catalyst Semiconductor’s EEPROM technology will strengthen our custom application-specific
circuits (ASIC) and power products capabilities expanding our ability to more comprehensively address our
customers’
needs.  With the combination of ON Semiconductor's global footprint, effective channels of
distribution, and top-tier customer relationships, we expect to be able to support a broader and deeper
penetration of Catalyst's overall product portfolio.  This should enable us to accelerate their revenue growth
and increase market share.  We also believe additional revenue from Catalyst Semiconductor’s strong
portfolio offering will benefit from ON Semiconductor’s manufacturing capabilities.  We look forward to
welcoming Gelu Voicu, Catalyst Semiconductor’s CEO, as well as the talented Catalyst employee base to
ON Semiconductor.”


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ON Semiconductor to Acquire Catalyst Semiconductor, Inc. in an All-Stock Transaction
Continued
“This transaction represents a compelling opportunity for Catalyst employees, customers and shareholders,”
stated Gelu Voicu, CEO of Catalyst Semiconductor.  “To compete successfully in today’s global marketplace,
size and scale are very important.  We are pleased to become part of a leading global company in the
semiconductor sector.  ON Semiconductor’s world-class operational capabilities and supply chain will enable
Catalyst Semiconductor’s products to better penetrate the automotive, consumer, and industrial end-markets
utilizing ON Semiconductor’s global customer and channel footprint.“
Transaction Details
Under the terms of the agreement, which has been approved by both boards of directors, the fixed exchange
ratio will be 0.706 shares of ON Semiconductor common stock for each share of Catalyst Semiconductor
common stock.  Based on the closing stock price of ON Semiconductor on July 16, 2008, this represents a
value to Catalyst Semiconductor shareholders of approximately $6.24 per share.  Upon completion of the
transaction, ON Semiconductor will issue approximately 13 million shares of common stock on a fully diluted
basis to complete the transaction or approximately 3 percent of ON Semiconductor’s fully diluted shares
outstanding.
The transaction is subject to the approval of shareholders of Catalyst Semiconductor as well as customary
closing conditions and regulatory approvals.  The companies expect the transaction to close in the fourth
quarter of 2008.  Upon closing, ON Semiconductor may record a one-time charge for purchased in-process
research and development expenses and other deal related costs.
The amount of that charge, if any, has not
yet been determined.    


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ON Semiconductor to Acquire Catalyst Semiconductor, Inc. in an All-Stock Transaction
Continued
“This
acquisition
is
directly
aligned
with
both
our
strategic
and
financial
goals,”
said
Donald
Colvin,
ON
Semiconductor executive vice president and CFO.  “Net of cash and short term investments of approximately
$30 million at the end of April 2008, the transaction value represents approximately 1.1 times trailing twelve
month sales.  We also believe ON Semiconductor’s operational strengths will significantly benefit the revenue
and margin potential of Catalyst Semiconductor.  Excluding the impact of amortization expense, write-up of
inventory to fair market value, one-time and other deal related charges discussed above, we expect the
acquisition will have minimal impact to earnings per share in the first year post the transaction close and
should be accretive to our earnings per share thereafter.  ON Semiconductor’s business and the integration
of AMIS Holdings, Inc. has proceeded as anticipated and we are comfortable with the guidance and current
level of revenue and earnings expectations provided on our May 5, 2008 conference call.  We intend to
provide further details on the acquisition and our second quarter 2008 results on our regularly scheduled
quarterly earnings conference call on Aug. 6, 2008.”
Shares of the combined company will trade on the NASDAQ Global Exchange under the symbol “ONNN.”
JP Morgan acted as exclusive financial advisor and DLA Piper US LLP acted as legal counsel to ON
Semiconductor. Houlihan Lokey acted as exclusive financial advisor and O’Melveny & Myers LLP acted as
legal counsel to Catalyst Semiconductor.


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Call Agenda
ON Semiconductor / Catalyst Semiconductor Announcement
Catalyst Semiconductor Overview
Customer Communication
Expectations from Sales and Marketing and Customer Facing
Teams


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor


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Catalyst Semiconductor
Top Distributors
Arrow
Avnet (incl Memec Div)
Digi-Key
Future
Kanematsu
Pernas
Yosun


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Call Agenda
ON Semiconductor / Catalyst Semiconductor Announcement
Catalyst Semiconductor Overview
Customer Communication
Important Information
Expectations from Sales and Marketing and Customer Facing
Teams


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TO:
Our Valued Customers, Sales Representatives and Distributors
DATE:
July 17, 2008
SUBJ:
Acquisition of Catalyst Semiconductor by ON Semiconductor
Today ON Semiconductor announced the signing of a definitive merger agreement providing for the acquisition of Catalyst
Semiconductor Inc.  The transaction is subject to the approval of shareholders of Catalyst Semiconductor as well as
customary closing conditions and regulatory approvals.  The companies expect the transaction to close in the fourth quarter of
2008.  I would like to share with you the vision of a technologically broader and operationally stronger company serving your
needs.
The
acquisition
of
Catalyst
Semiconductor
will
add
to
our
analog
and
mixed-signal
product
offerings
for
the
telecommunications, networking systems, computing, automotive, industrial and consumer markets.   Catalyst
Semiconductor’s EEPROM technology will strengthen our custom application-specific circuits (ASIC) and power products
capabilities
expanding
our
ability
to
more
comprehensively
address
our
customers’
needs.
With
the
combination
of
ON
Semiconductor's global footprint, effective channels of distribution, and top-tier customer relationships, we expect to be able to
support a broader and deeper penetration of Catalyst's overall product portfolio.
Operationally it will be business as normal for customers.  We will communicate any potential changes to you at the earliest
possible time, but ask that you continue to do business using your normal contacts and processes for Catalyst Semiconductor
products.
We remain committed to providing you with outstanding customer service, advanced technology solutions, industry-leading
supply chain management, and world-class quality and manufacturing.  We look forward to a long and mutually beneficial
relationship.
If
you
have
any
questions
or
concerns,
please
contact
your
local
sales
contact.
You
may
e-mail
questions
to
transitions@onsemi.com.
Best Regards,
Keith Jackson
President and CEO
ON Semiconductor
Customer Letter for Sales Use


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Key Talking Points
Talking Points
On July 17, ON Semiconductor announced the signing of a definitive merger agreement providing for the acquisition of
Catalyst Semiconductor by ON Semiconductor in an all-stock transaction in which Catalyst shareholders will receive 0.706
shares of ON Semiconductor common stock for each share of Catalyst common stock they own.
Benefits of the deal
The acquisition of Catalyst Semiconductor will add to ON Semiconductor’s analog and mixed signal products offerings
Catalyst’s EEPROM technology will strengthen ON Semiconductor’s ASIC and power products capabilities expanding ON
Semiconductor's
ability
to
more
comprehensively
address
its
customers’
needs
The EEPROM segment provides a new total available market (TAM) opportunity for ON Semiconductor of approximately $800
million to $1 billion
With the combination of ON Semiconductor's global footprint, effective channels of distribution, and top-tier customer
relationships, ON Semiconductor expects to be able to support a broader and deeper penetration of Catalyst's overall product
portfolio
Catalyst has a long history of developing proprietary Intellectual Property (IP) and proven designs.
Catalyst Semiconductor’s strong portfolio offering should also benefit from ON Semiconductor’s integrated manufacturing
capabilities. The acquisition also further enhances the utilization of the Gresham facility
To compete successfully in today’s global marketplace, size and scale are important. ON Semiconductor provides Catalyst
with:
-
Enhanced scale
-
Deeper customer relationships and sales channels
-
Integrated manufacturing capabilities
-
An expanded addressable market
Next Steps
We
expect
the
deal
to
close
sometime
during
the
fourth
quarter
of
2008
The company will continue the integration of AMIS processes prior to integrating Catalyst Semiconductor
ON
Semiconductor
intends
to
have
Catalyst
Semiconductor
operate
as
a
stand
alone
basis
for
the
foreseeable
future
Look for ongoing acquisition and integration updates on The Connection or The Circuit


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Customer and Employee Escalation
Email address used to handle questions:
Questions to: transitions@onsemi.com
Transition team members will be managing and answering these
common email accounts for the next several weeks


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Call Agenda
ON Semiconductor / Catalyst Semiconductor Announcement
Catalyst Semiconductor Overview
Customer Communication
Expectations from Sales and Marketing and Customer Facing
Teams


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What We Expect From You?
Sales / Customer Service to be in contact with each other to ensure
customer is communicated to appropriately, and no duplication of
efforts.
Convey the message to all customers that it is business as usual
Continue to use their Catalyst Sales contact and processes
The acquisition is anticipated to close during the fourth quarter of 2008, but
is subject to Catalyst shareholder approval and other normal regulatory
requirements
Use the communication materials provided to keep customers informed
Report
back
to
transitions@onsemi.com
any
customer
concerns
and
issues that need to be escalated.


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FAQ’s
FREQUENTLY ASKED QUESTIONS
Transaction Summary
What does the announcement mean?
ON Semiconductor and Catalyst Semiconductor have signed a definitive merger agreement providing for the acquisition of
Catalyst Semiconductor by ON Semiconductor in an all-stock transaction. At the closing date, if you own shares of Catalyst
Semiconductor
common
stock,
you
would
receive
0.706
shares
of
ON
Semiconductor
common
stock
for
each
shared
owned
of Catalyst Semiconductor. If you have Catalyst Semiconductor stock options, they will be exchanged for options which
represent 0.706 shares of ON Semiconductor stock options for each Catalyst Semiconductor stock option owned. The
exercise price of the options would take the original stock option grant price divided by 0.706 to calculate the new exercise
price.
Why does ON Semiconductor want to acquire Catalyst Semiconductor?
•Catalyst Semiconductor adds to the high gross margin analog and mixed-signal product offerings for the digital consumer
and wireless end-markets of ON Semiconductor
•Catalyst
Semiconductor’s
analog
and
mixed-signal
business
represented
more
than
$11
million
in
sales
as
of
their
April
2008
fiscal
year
end
-
a
business
that
grew
more
than
90
percent
versus
the
prior
year
•Catalyst expands our product offering into the non-volatile memory market
•Catalyst Semiconductor’s EEPROM technology will strengthen our custom application-specific circuits (ASIC) and power
products
capabilities
expanding
our
ability
to
more
comprehensively
address
our
customers’
needs
•Additional revenue from Catalyst Semiconductor’s strong portfolio offering will benefit from ON Semiconductor’s
manufacturing capabilities
Does the announcement mean a deal has been finalized?
This transaction is not done. There are a number of processes and government filings that we need to complete before the
deal is closed. We currently expect the deal to close in ON’s fourth quarter of 2008 subject to the approval of Catalyst
shareholders as well as customary closing conditions and regulatory approvals.
Do ON Semiconductor shareholders have to approve the transaction?
ON Semiconductor shareholders are not required to vote and approve the pending transaction. 
Only Catalyst Semiconductor shareholders will need to vote and approve the pending transaction. A Catalyst shareholder
meeting
will
most
likely
take
place
during
the
fourth
quarter
of
2008.
How many Catalyst employees are impacted by this decision?
All
of
the
approximately
250
Catalyst
employees
will
be
directly
impacted
by
this
decision.


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FAQ’s
FREQUENTLY ASKED QUESTIONS
How many Catalyst employees will be offered a position at ON Semiconductor?
Substantially all of the Catalyst employees will be offered a position.
Where are the majority of the employees involved in this deal located?
The majority of employees are located in Santa Clara, California, Bucharest, Romania and Thailand with field sales and other
employees dispersed throughout the world.
What resources will ON Semiconductor utilize for the purchase?
This will be an all stock transaction.
The press release mentioned enterprise value. What does that mean?
Enterprise value is a measure of a company’s value. It is calculated as the market capitalization (share price x shares
outstanding) plus any debt minus cash and short term investments.
What should I tell my customers about the acquisition?
If asked, tell customers that the deal is still pending subject to the official close. However, if the deal is completed, there are
long-term
benefits
to
customers
including
stronger
product
portfolio,
integrated
sales
channels,
integrated
manufacturing
capabilities to meet demand changes and enhanced scale.
What if customers ask me questions that I don’t know the answers to?
If you don’t know the answers, it’s okay to say that you don’t know, but that you will find out and get back to them. The best
way to do this is to contact your manager.
What should I do if a journalist asks me a question?
Please direct all media inquiries to the media relations department of ON Semiconductor.
ON Semiconductor
Anne Spitza
Manager, media relations
(602) 244-6398
anne.spitza@onsemi.com
Catalyst Semiconductor
Sherry Hill
Director, Marketing & IR Communications
(408) 542-1080
Sherry.hill@catsemi.com


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FAQ’s
FREQUENTLY ASKED QUESTIONS
Acquisition Background
Who is Catalyst Semiconductor?
Catalyst Semiconductor (NASDAQ:CATS) is committed to helping today's electronics designers balance system performance
and board costs with a rapidly growing portfolio of analog, mixed-signal and non-volatile memory ICs for telecommunications,
networking systems, computation, automotive, industrial and consumer markets.
Products include Digitally Programmable Potentiometers [DPP™], white and color LED drivers, DC/DC converters, voltage
supervisors, I/O expanders, serial and parallel EEPROMs, Flash memories, and NVRAMs. Typical applications for ICs include
LCD displays, cellular phones, automotive illumination and instrumentation, optical networks, wireless LANs, network cards,
DIMM modules, printers, digital satellite box receivers and set-top boxes.
The Catalyst headquarters facility is located in Santa Clara, California with regional sales operations and technical support
offices in China, Korea, Taiwan, Thailand, Southeast Asia, Japan, UK, Germany and the Americas. The company’s strategy is
to combine a fabless business model with in-house design centers in Santa Clara, California and Bucharest, Romania to
provide customers with the high-performance and low-cost required for success in today's electronics markets.
For
more
information
visit
http://www.catsemi.com/
When do you expect the deal to close?
We expect to close the deal within sometime during ON’s fourth quarter of 2008 subject to Catalyst shareholder and regulatory
approval and the satisfaction of customary closing conditions.
What happens after this initial announcement?
Work will continue on all levels to finalize details needed to close the sale.


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FAQ’s
FREQUENTLY ASKED QUESTIONS
About ON Semiconductor
Who is ON Semiconductor?
ON Semiconductor (Nasdaq: ONNN) is a preferred supplier of power
solutions to engineers,
purchasing professional, distributors, and contract manufacturers in the computer, cell phone, portable
devices, automotive and industrial markets.
They design, manufacture and market an extensive portfolio of semiconductor components that
addresses the design needs of sophisticated electronic systems and products.
•Their power management semiconductor components distribute and monitor the supply of power to the different
elements within a wide variety of electronic devices.
•Their data management semiconductor components provide high-performance clock management and data
flow management for precision computing and communications systems.
•Their
standard
semiconductor
components
serve
as
“building
block”
components
within
virtually
all
electronic
devices.
For more details please go to our Web site at www.onsemi.com
Where is the ON Semiconductor’s headquarters?
The company is headquartered in Phoenix, Arizona, USA. The company owns and operates several development centers and
several manufacturing facilities located throughout the U.S., Europe and Asia.
How many employees are employed by ON Semiconductor?
Worldwide, ON Semiconductor employs more than 14,000 employees.
What is ON Semiconductor’s company mission?
To provide our customers with high quality, cost-effective solutions to solve the demanding power and signal management
design challenges.
What is ON Semiconductor’s company vision?
ON Semiconductor is dedicated to becoming the premier supplier of high performance energy efficient silicon solutions
worldwide.


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FAQ’s
FREQUENTLY ASKED QUESTIONS
What is ON Semiconductor’s business strategy?
•ON Semiconductor’s business strategy is to become the supplier of choice by:
•Leveraging our operational strengths
•Building intimate relationships with market-making customers
•Improving our technological capabilities to provide leadership in power and signal management solutions
What is ON Semiconductor’s Quality/Service philosophy/statement?
ON Semiconductor’s Quality statement is: “Every ON Semiconductor employee is personally responsible for ensuring the
highest quality in products and services delivered to internal and external customers. Continuous improvement in the quality of
processes, products, and service is fundamental to the achievement of customer satisfaction.”