Tkool Electronics

The two new products offer a small package size of 15 mm x 15 mm, making them well-suited to record, play and transmit superior picture-quality HD video on portable devices, such as digital camcorders, as well as on home networked appliances, commercial broadcast equipment and security cameras.

RWR80S7R15FRS74_Datasheet PDF

The two new products offer a small package size of 15 mm x 15 mm, making them well-suited to record, play and transmit superior picture-quality HD video on portable devices, such as digital camcorders, as well as on home networked appliances, commercial broadcast equipment and security cameras.

Although focus on the energy problem has ebbed and flowed over the past 20 to 25 years, the conversation always comes back to the fact that we're using more and more energy. In the high-tech industry, the energy problem has not gone unnoticed (some might argue that it hasn't been taken very seriously). For example, in 2005, server farms in the U.S. accounted for 1.2% of the total electricity used. Today, that number is 12%. Comparatively, total electricity consumption today is divided among electric motors, electronics equipment, and cars at approximately 33% each.

So, what have we done to solve the problem? Over the past 20 years, designers' concerns have rotated between power, integration, price, and form factor. In 2008, awareness of the energy problem was increasing, but so too were price and footprint pressures from an exploding power-sensitive portable and consumer marketplace. Although new ultra-low-power ICs, power-optimized tools, and power-smart intellectual property emerged, we didn't do as much as we should have at that time.

RWR80S7R15FRS74_Datasheet PDF

To address the whole energy problem, we should have quickly established the capability to generate the additional energy required to power all of these electric cars without having to use coal. We should have developed a modified Energy Star program for the electronics industry sooner. We should have designed for minimum power and the environment instead of for maximum performance. Had designers of electronic equipment abided by the rule: if low-power components are available, use them,” we might not be in this situation–needing more and more energy and still relying on coal and foreign oil.

Ah, if only I had a solar-powered time machine. Besides the obvious perks of time travel, I could go back to 2008 and invest in sunblock stocks and ice makers because it's hot, hot, hot!

John East is president and CEO of Actel. Prior to joining Actel in 1988, he held various positions at AMD, Raytheon Semiconductor and Fairchild Semiconductor.

RWR80S7R15FRS74_Datasheet PDF

Low voltage amplifiers are often used in single-supply voltage circuits and make use of the rail-to-rail output feature these amplifiers have. While the output of these amplifiers can swing close to zero volts, they do not reach zero volts at the output. This can cause problems when driving analog/digital converters (ADC) due to the loss of some portion of the low side of the ADC's input range. In another case, when amplifiers are used in a series of gain stages, the saturated output of an amplifier is amplified by the gain of the succeeding stage, and the minimum output is the output saturation of the first stage multiplied by the gain of the succeeding stage.

This problem with low-voltage amplifiers in a single-supply voltage application can be fixed by supplying a small, negative-supply voltage to the amplifier. This voltage enables the amplifier's output to swing to zero volts while keeping the total supply voltage at less then the maximum operating-supply voltage specification of the amplifier. This article discusses several methods of creating small, negative-supply voltages for use with amplifiers.

RWR80S7R15FRS74_Datasheet PDF

The Problem In many cases, sensor signal conditioning requires that a sensor's output be scaled to a range that includes zero volts. For example, in Figure 1, an ADC is using a 2.5-volt reference voltage so the ADC's input range is 0 to 2.5 volts. To use the full dynamic range of the ADCs input span, the sensor's output is required to be scaled to range from 0 to 2.5 V.

When amplifiers are operated from a single-supply voltage, the outputs will not swing to zero volts, and rail-to-rail outputs will have some output-saturation voltage relative to ground. In the sensor's signal-conditioning path, the result is the loss of the lower range of the ADC's input.

Software-enhanced optics provides a means for delivering a fully automatic solution for camera phones that enables the consumer to obtain clear images under a wide range of luminance conditions. The basis of the approach is to design the camera module with low F-number optics, typically F/1.75, and restore the depth of field to normal using the extended field depth solution described above. The low F-number optics makes the ultra fast lens solution suitable for both still photography as well as video feeds. The signal processing compensates for loss of contrast and substantially reduces noise in the final image, while preserving edges, fine details and texture. This is possible because the information written to the line buffers necessary to run the algorithms can be reused to provide pixel-averaging data and improve the signal-to-noise ratio of the image by up to 6dB. The effectiveness of this solution can be clearly discerned by comparing the two photographs, taken with identical imagers having 1.75μm pixels, in Figure 9.

Implementation Software-enhanced optics combines a special lens with a custom algorithm to deliver remarkable quality pictures in a way that is totally transparent to the consumer. However, the camera module designer needs to think ahead to incorporate these image enhancement technologies in a handset, as it cannot be done as an add-on. In principle, all that is required is one custom-designed lens in the optics train that can be manufactured using the existing infrastructure and lens materials. The custom lens can even substitute for an existing lens. Allied with this is the image processing algorithm. The algorithms for these solutions are usually small, taking approximately 100k gates. This is small enough for the algorithm to be embedded in the image pipeline on the CMOS imager, but clearly requires co-operation with the image sensor manufacturer, and the die must then be married to the correct optics.

The alternative placement for the algorithm is as software or firmware running on a dedicated image processor or the phone processor. Again, both of these solutions are very simple from a technical standpoint but require communication outside of the traditional camera module supply chain. Nevertheless, the benefits of these solutions are so compelling that 3Mpixel camera phones with extended field depth are already in production and will be proliferating–together with zoom and ultra fast lens solutions–to higher resolution cameras in 2009.

While software-enhanced optics work to boost the raw performance of highly miniaturized and low-cost camera modules, apart from the zoom solution, they do little to provide features that stoke customer satisfaction with the picture-taking experience. This issue matters little to the camera module designer, but is of very great importance to the original equipment manufacturer. One of the most commonly encountered annoyances from digital camera photographs is red-eye, which explains why red-eye reduction is today implemented on more than 80 percent of digital still cameras. Whether features such as this can be provided on camera phones and how they can be integrated is discussed in Part 4 of this article series.

访客,请您发表评论:

Powered By Tkool Electronics

Copyright Your WebSite.sitemap