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Volume 29 (Sep 30, 2004)
Mobile CMADS: Bringing new design to mobile telephones
Mobile telephone design that changes according to the phone's intended purpose
Mobile phones have fast become an integral part of our daily lives. In fact, the pervasion of mobile phones has reached the point where nearly everyone owns one. In addition to being used for their original intended purpose, mobile phone have also become multifunctional-they now can be used to write e-mail, surf the Internet and take pictures just as you would with a digital camera. Furthermore, services such as videophoning and moving image transmission are expected to gain popularity in the future.
In accordance with this, the design of mobile phones has also begun to change. Back when they were primarily used for verbal communication purposes, mobile phones that were compact, lightweight and straight in shape were the norm. Then, as users began to use their mobile phones for sending e-mail and surfing the Internet, it became necessary to increase the size of the display screen and foldable handsets prevailed. Presently, as 3G mobile telephones begin to gain momentum, demand for mobile phones designed for videophoning and moving image transmission use is increasing. As a result, mobile phones equipped with displays that can be rotated a full 180 degrees and those capable of two-axle rotation are starting to appear on the market (Figure 1).
Mobile CMADS: Expanding possibilities for mobile handset phone design
As mobile phones designs become increasingly diversified, one of the problems faced by manufacturers is that they find themselves restricted in terms of design due to factors such as data transfer between the main body of the handset and the liquid crystal display (LCD) panel. To help manufacturers address this problem, NEC Electronics introduced the Mobile CMADS high-speed serial interface standard. And to make adoption of this standard even simpler, we have commenced shipment of samples of the Mobile CMADS-compatible µPD161451 bridge IC (Photo 1).
Designed for use in the main body of a mobile phone, the µPD161451 converts parallel- formatted data to serial-formatted data and then transmits the converted data to the LCD driver IC housed in the LCD panel. The Mobile CMADS-compatible LCD driver IC is already available (Figure 2).
Since the amount of data signal wiring can be reduced from the conventional 18 lines to 4 lines through the use of these products, the hinges connecting the main body of the handset and the LCD panel can be narrowed considerably, thereby allowing manufacturers more freedom in designing mobile phones (Figure 3).
In addition, the Mobile CMADS system makes it possible to maintain low power consumption and reduce electromagnetic (EMI) noise during data transmission, as well as conduct high-speed transmission of large-volume data such as moving images with as little impact on transmission/call time and quality as possible.
Providing solutions for mobile phones
To meet the needs of its customers, NEC Electronics was among the first to launch development of a LCD driver IC for mobile phones. Combined use of the Mobile CMADS-compatible bridge IC and LCD driver IC not only makes it possible for handset design to be carried out more freely due to a reduction in the amount of data signal wiring, but also contributes to the development of mobile handsets thanks to the realization of large-volume and high-speed data transmission while maintaining low power consumption and reducing EMI noise. In the future, NEC Electronics will continue to provide solutions that correspond with the trend toward high-performance, multifunctional mobile phones.
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