Oki Electric, First in the Industry to Develop a Single Chip LSI for Radio Controlled Clocks
- Using Japan's Long-wave Standard Time Code -

"We are proud to announce the industry's first single chip LSI for radio controlled clocks, based on Japan's long-wave standard time code ^*2, " said Akira Kamo, President of the Silicon Solutions Company at Oki Electric. "With this LSI, our customers who manufacture radio controlled clock embedded equipment can benefit a large amount because the single chip significantly reduces cost and development time for such equipment."

Radio controlled clocks are in high demand as they can adjust time by standard time code compared to regular clocks that easily lose their accuracy. The radio controlled clocks are mostly composed of several LSIs, an antenna, and a crystal resonator. The LSIs include a signal receiver LSI ^*3 based on an analog circuit, a decoder LSI ^*4 and an RTC LSI both based on a digital circuit. In addition to these three LSIs, decoder software is needed to extract time from the received signal when developing a radio controlled clock. Adjustments between the signal receiver LSI and the antenna and crystal resonator are also necessary, which consumes time and increases costs of development.

Conventional analog circuits are based on bipolar processes, while digital circuits are based on CMOS processes. Because of the different process technologies, it was difficult to produce LSIs for radio controlled clocks onto a single chip. However, in Oki's ML6191, the signal receiver LSI, decoder LSI, and RTC LSI are manufactured on SOI (Silicon on Insulator)-CMOS ^*5 process technology, a technology that stands out in mixing analog and digital circuit. Combining the functions onto a single chip eliminates the decoder software development and reduces the square size and power consumption. In addition, by using an antenna and a crystal resonator recommended by Oki, manufactures can easily adjust these components to the ML6191.

Oki became the first in the industry to successfully create an LSI with a receiver function, decoder function and real time clock function all on a single chip, utilizing its abundant track records of digital/analog design technology, decoding technology, and adopting SOI-CMOS process technology. This chip can be used as an RTC LSI with an automatic time adjusting function and is suitable for use in general appliances including audiovisual equipment, home appliances, PCs, and car clocks.

With Oki's assets in designing LSIs and its SOI-CMOS process technology, the company plans to integrate remote control functions, sensor control functions and various interface functions into a single chip to enhance its product line-up.

[Features of ML6191]

• Automatically receives Japan's Long-wave Standard Time Code
• Set reception time and reception interval
• Automatically shifts the two time code transmitters in Japan (40kHz or 60kHz)
• Choose mandatory reception or automatic reception
• Choose the 12 hour system or the 24 hour system
• Clock output of 32.768kHz
• Serial interface
• Radio signal sensitivity: Typ. 0.7µVrms
• Supply voltage range: 1.1-3.6V
• Low consumption current: 0.25µA at HALT (standby detection 32kHz)
• Operating temperature range: -40°C to 85°C

[Sales Plan]

• Sample shipment: May 2004 (32pin QFN)
• Sample price: 700 yen
• Volume shipment: September 2004
• Volume scale: 500 thousand per month

*1	Radio controlled clocks are accurate when compared to conventional clocks and also need no adjustment even before shipment, first use, battery changes or after blackouts. Radio controlled clocks are expected to be mounted into equipment such as audiovisual terminals, such as television and DVD recorders that need time settings to turn the power on and off, or to record programs, security equipment, such as monitoring systems to stamp accurate time, and business equipment, such as facsimiles and time recorders.
*2	Japan's long-wave standard time code is a highly accurate radio wave of Japan standard time with an accuracy of one second in 100 thousand years, operated by National Institute of Information and Communications Technology.
*3	Signal receiver LSI amplifies and detects the received standard time code and demodulates it into signal data.
*4	Decoder LSI converts signal data outputted from the signal receiver LSI to time information. This time information overwrites the time on the real time clock.
*5	SOI-CMOS is a technology to compose CMOS on an insulating film, using an SOI wafer with an embedded insulator instead of a conventional silicon wafer. As transistors are created on an insulation film, the chip consumes a low power current, which in turn, decreases the concomitant thermal noise. Noise transmitted from a substrate is also decreased, as transistors are completely isolated from the substrate by an insulation film.

About Oki Electric Industry Co., Ltd.
Founded more than a century ago in 1881, Oki Electric Industry Co., Ltd. is Japan's first telecommunications manufacturer, with its headquarter in Tokyo, Japan. With the corporate vision, "Oki, Network Solutions for a Global Society," Oki Electric provides top-quality products, technologies and solutions to its customers through its telecommunications systems, information systems and electronic devices segments. All three segments are integrated into one effective organization that functions as a collective force to create exciting new products and technologies, including information and telecom converged solutions. Through its business activities, Oki Electric satisfies a spectrum of customer needs in various markets.

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