This week, the overall grades of 22 Semiconductor stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Microsemi (NASDAQ:MSCC) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Microsemi designs, manufactures, and markets high-performance analog and mixed-signal integrated circuits and high-reliability semiconductors. In Portfolio Grader’s specific subcategories of Earnings Growth, Earnings Momentum, and Margin Growth, MSCC also gets an F. For more information, get Portfolio Grader’s complete analysis of MSCC stock.

Silicon Image (NASDAQ:SIMG) earns a F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). Silicon Image designs, develops, and markets semiconductor solutions for applications that require high-bandwidth, integrated solutions for high-speed data communications. The stock gets F’s in Equity and Margin Growth. The price of SIMG dropped 9.9% over the last month. This is worse than the 1.6% increase seen by the Nasdaq for the same period. To get an in-depth look at SIMG, get Portfolio Grader’s complete analysis of SIMG stock.

Skyworks Solution (NASDAQ:SWKS) experiences a ratings drop this week, going from last week’s C to a D. Skyworks Solutions is an innovator of analog and mixed-signal semiconductors. The stock price has fallen 20.7% over the past month. For a full analysis of SWKS stock, visit Portfolio Grader.

Freescale Semiconductor (NYSE:FSL) earns a F this week, falling from last week’s grade of D. Freescale Semiconductor provides embedded processing semiconductors and related solutions. The stock gets F’s in Earnings Revisions and Sales Growth. Wall Street appears to agree with the stock downgrade, with share prices dropping 13.8% over the past month. For more information, get Portfolio Grader’s complete analysis of FSL stock.

Lattice Semiconductor (NASDAQ:LSCC) is having a tough week. The company’s rating falls from a D to a F rating. Lattice Semiconductor designs, develops, and markets high speed programmable logic devices. In Earnings Growth, Earnings Momentum, Earnings Revisions, and Sales Growth the stock gets F’s. For a full analysis of LSCC stock, visit Portfolio Grader.

NXP Semiconductor‘s (NASDAQ:NXPI) rating weakens this week, dropping to a D versus last week’s C. NXP Semiconductors operates as a global semiconductor company. The stock gets F’s in Earnings Growth, Equity, and Margin Growth. To get an in-depth look at NXPI, get Portfolio Grader’s complete analysis of NXPI stock.

Slipping from a C to a D rating, Inphi Corp. (NYSE:IPHI) takes a hit this week. Inphi is a fabless provider of high-speed analog semiconductor solutions for the communications and computing markets. The stock gets F’s in Earnings Growth and Margin Growth. Investors seem to agree with the downgrade and have pushed down the share price 13.9% over the past month. For more information, get Portfolio Grader’s complete analysis of IPHI stock.

The rating of Supertex (NASDAQ:SUPX) slips from a D to a F. Supertex is a designer, developer, manufacturer and marketer of integrated circuits. The stock receives F’s in Earnings Growth, Earnings Revisions, Earnings Surprise, and Sales Growth. The trailing PE Ratio for the stock is 62.10. Shares of the company are down 0.3% from last month. To get an in-depth look at SUPX, get Portfolio Grader’s complete analysis of SUPX stock.

This is a rough week for Silicon Laboratorie (NASDAQ:SLAB). The company’s rating falls to D from the previous week’s C. Silicon Laboratories designs and develops proprietary, analog-intensive and mixed-signal integrated circuits that can be used in a range of applications. The stock has a trailing PE Ratio of 27.80.  Shares of SLAB are down 5% from a month prior. For a full analysis of SLAB stock, visit Portfolio Grader.

United Microelectronics (NYSE:UMC) earns a D this week, moving down from last week’s grade of C. United Microelectronics is a semiconductor wafer foundry that provides wafer fabrication services and technologies. The stock gets F’s in Cash Flow, Margin Growth, and Sales Growth. The price of UMC stayed flat from a month ago. To get an in-depth look at UMC, get Portfolio Grader’s complete analysis of UMC stock.

Teradyne (NYSE:TER) gets weaker ratings this week as last week’s C drops to a D. Teradyne is a designer, manufacturer and global supplier of automatic systems and solutions used to test complex electronics. Share prices fell 9% over the past month. As of Sept. 26, 2012, 10.6% of outstanding Teradyne shares were held short. For more information, get Portfolio Grader’s complete analysis of TER stock.

This week, Aixtron (NASDAQ:AIXG) drops from a D to a F rating. Aixtron provides deposition equipment, such as that used in lighting, fiber optic communication systems, and mobile telephone applications, to the semiconductor industry. The stock receives F’s in Earnings Growth, Earnings Momentum, and Earnings Revisions. Equity, Margin Growth, and Sales Growth also get F’s. Over the last month, shares of AIXG dropped 7.9%. For a full analysis of AIXG stock, visit Portfolio Grader.

The rating of IXYS Corp. (NASDAQ:IXYS) declines this week from a D to a F. IXYS designs, develops, and markets power semiconductors. The stock gets F’s in Earnings Momentum, Earnings Revisions, and Sales Growth. For more information, get Portfolio Grader’s complete analysis of IXYS stock.

This week, Integrated Device Technology‘s (NASDAQ:IDTI) rating worsens to a F from the company’s D rating a week ago. Integrated Device Technology designs, develops, manufactures, and markets a variety of semiconductor products and modules. The stock gets F’s in Earnings Growth, Earnings Momentum, Margin Growth, and Sales Growth. For a full analysis of IDTI stock, visit Portfolio Grader.

This is a rough week for Kulicke & Soffa (NASDAQ:KLIC). The company’s rating falls to D from the previous week’s C. Kulicke & Soffa designs, manufactures, and markets capital equipment, related spare parts, and packaging materials used to assemble semiconductor devices. The stock also gets an F in Sales Growth. The stock price has fallen 10.8% over the past month. To get an in-depth look at KLIC, get Portfolio Grader’s complete analysis of KLIC stock.

This week, Diodes (NASDAQ:DIOD) drops from a D to a F rating. Diodes designs, makes, and supplies high-quality, application-specific standard products within the discrete and analog semiconductor markets, as well as in the consumer electronics, computing, communications, industrial, and automotive markets. The stock receives F’s in Earnings Growth, Earnings Revisions, Earnings Surprise, and Margin Growth. The stock’s trailing PE Ratio is 34.00. Shares of the company are down 6.1% from last month. For a full analysis of DIOD stock, visit Portfolio Grader.

Analog Devices (NASDAQ:ADI) earns a D this week, falling from last week’s grade of C. Analog Devices is engaged in the design, manufacture and marketing of high-performance analog, mixed-signal and digital signal processing integrated circuits used in industrial, communication, computer and consumer applications. The stock also rates an F in Sales Growth. The price of ADI is down 1.8% since last month. To get an in-depth look at ADI, get Portfolio Grader’s complete analysis of ADI stock.

Slipping from a D to a F rating, Kopin Corp. (NASDAQ:KOPN) takes a hit this week. Kopin develops and manufactures semiconductor materials and small form factor displays. In Earnings Growth, Earnings Revisions, Margin Growth, and Sales Growth the stock gets F’s. For more information, get Portfolio Grader’s complete analysis of KOPN stock.

OmniVision Technologies (NASDAQ:OVTI) experiences a ratings drop this week, going from last week’s D to a F. OmniVision Technologies provides integrated single chip semiconductor imaging devices. The stock gets F’s in Earnings Growth, Earnings Momentum, and Margin Growth. Share prices fell 7.3% over the past month. As of Sept. 26, 2012, 17.6% of outstanding OmniVision Technologies shares were held short. The stock currently has a trailing PE Ratio of 32.30. To get an in-depth look at OVTI, get Portfolio Grader’s complete analysis of OVTI stock.

Micron Technology (NASDAQ:MU) is having a tough week. The company’s rating falls from a D to a F rating. Micron Technology manufactures and markets Dram and Nand Flash memory, image sensors and other semiconductor components. The stock gets F’s in Earnings Growth, Equity, Cash Flow, and Margin Growth. The stock price fell 3.1% over the past month. For more information, get Portfolio Grader’s complete analysis of MU stock.

LTX-Credence (NASDAQ:LTXC) earns a F this week, moving down from last week’s grade of D. LTX-Credence designs, manufactures, and markets automatic test equipment for the semiconductor industry. The stock receives F’s in Earnings Growth, Earnings Revisions, and Equity. Margin Growth and Sales Growth also get F’s. Shares of the company are down 7.9% from a month ago. For a full analysis of LTXC stock, visit Portfolio Grader.

QuickLogic‘s (NASDAQ:QUIK) rating weakens this week, dropping to a D versus last week’s C. QuickLogic is the inventor and provider of customizable semiconductor solutions for mobile and portable electronics. The stock gets F’s in Equity, Cash Flow, and Sales Growth. For more information, get Portfolio Grader’s complete analysis of QUIK stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.