The following is a summary of revenue by product family for the periods indicated (in millions):

"MPS had an outstanding fourth quarter with 31.8 percent year-over-year revenue growth, which was much better than the overall analog market," said Michael Hsing, CEO and founder of MPS. "This was MPS's best Q4 and the best year yet in our history.  We continue to deliver on our growth strategy as evidenced by revenue diversification and growth far exceeding the analog industry.  We are confident in our future growth."

Business Outlook

The following are MPS' financial targets for the first quarter ending March 31, 2014:

• Revenue in the range of $58 million to $62 million.
• Gross margin between 53.5% and 54.5%.
• GAAP R&D and SG&A expenses between $26.3 million and $29.5 million. Non-GAAP(1) R&D and SG&A expenses between $20.0 million and $22.5 million. This excludes an estimate of stock-based compensation and deferred compensation plan expenses in the range of $6.3 million to $7.0 million.
• Litigation expense between $200,000 and $400,000.
• Fully diluted shares outstanding between 39.5 million and 39.9 million before shares buyback.

(1) Non-GAAP net income, non-GAAP earnings per share, non-GAAP operating expenses and non-GAAP R&D and SG&A expenses differ from net income, earnings per share, operating expenses, R&D and SG&A expenses determined in accordance with GAAP (Generally Accepted Accounting Principles in the United States). Non-GAAP net income and non-GAAP earnings per share for the quarter and year ended December 31, 2013 and 2012 exclude the effect of stock-based compensation expenses, deferred compensation plan expenses, a one-time benefit from a cash award and their related tax effects. Non-GAAP operating expenses for the quarter and year ended December 31, 2013 and 2012 exclude the effect of stock-based compensation and deferred compensation plan expenses. Projected non-GAAP R&D and SG&A expenses exclude the effect of stock-based compensation and deferred compensation plan expenses. These non-GAAP financial measures are not prepared in accordance with GAAP and should not be considered as a substitute for, or superior to, measures of financial performance prepared in accordance with GAAP. A schedule reconciling non-GAAP financial measures is included at the end of this press release. MPS utilizes both GAAP and non-GAAP financial measures to assess what it believes to be its core operating performance and to evaluate and manage its internal business and assist in making financial operating decisions. MPS believes that the inclusion of non-GAAP financial measures, together with GAAP measures, provides investors with an alternative presentation useful to investors' understanding of MPS' core operating results and trends. Additionally, MPS believes that the inclusion of non-GAAP measures, together with GAAP measures, provides investors with an additional dimension of comparability to similar companies. However, investors should be aware that non-GAAP financial measures utilized by other companies are not likely to be comparable in most cases to the non-GAAP financial measures used by MPS.

Conference Call

MPS plans to conduct an investor teleconference covering its quarter and year ended December 31, 2013 results at 2:00 p.m. PT / 5:00 p.m. ET, February 6, 2014. To access the conference call and the following replay of the conference call, go to http://ir.monolithicpower.com and click on the webcast link. From this site, you can listen to the teleconference, assuming that your computer system is configured properly. In addition to the webcast replay, which will be archived for all investors for one year on the MPS website, a phone replay will be available for seven days after the live call at (404) 537-3406, code number 33431773. This press release and any other information related to the call will also be posted on the website.

Safe Harbor Statement

This press release contains forward-looking statements, as that term is defined in the Private Securities Litigation Reform Act of 1995, including, among other things, (i) projected revenues, gross margin, GAAP and non-GAAP R&D and SG&A expenses, stock-based compensation expenses, deferred compensation plan expenses, litigation expense and diluted shares outstanding for the quarter ending March 31, 2014, (ii) our outlook for the long-term prospects of the company, including the prospects of our new product families, (iii) our ability to penetrate new markets and expand our market share, (iv) the seasonality of our business, (v) our ability to reduce our expenses, and (vi) statements of the assumptions underlying or relating to any statement described in (i), (ii), (iii), (iv) or (v). These forward-looking statements are not historical facts or guarantees of future performance or events, are based on current expectations, estimates, beliefs, assumptions, goals, and objectives, and involve significant known and unknown risks, uncertainties and other factors that may cause actual results to be materially different from the results expressed by these statements. Readers of this press release and listeners to the accompanying conference call are cautioned not to place undue reliance on any forward-looking statements, which speak only as of the date hereof. Factors that could cause actual results to differ include, but are not limited to, our ability to attract new customers and retain existing customers; acceptance of, or demand for, MPS' products, in particular the new products launched within the past 18 months, being different than expected; competition generally and the increasingly competitive nature of our industry; any market disruptions or interruptions in MPS' schedule of new product release development; adverse changes in production and testing efficiency of our products; adverse changes in government regulations in foreign countries where MPS has offices or operations; the effect of catastrophic events; adequate supply of our products from our third-party manufacturer; the risks, uncertainties and costs of litigation in which we are involved; the outcome of any upcoming trials, hearings, motions and appeals; the adverse impact on MPS' financial performance if its tax and litigation provisions are inadequate; adverse changes or developments in the semiconductor industry generally; difficulty in predicting or budgeting for future customer demand and channel inventories, expenses and financial contingencies; and other important risk factors identified in MPS' Securities and Exchange Commission (SEC) filings, including, but not limited to, its quarterly report on Form 10-Q filed with the SEC on October 28, 2013 .