Oki Semiconductor Announces Voice Linear Codec for Digital Handsets; New Chip Integrates 100 mW Dynamic Speaker Driver Eliminating Discrete Op Amp.

Business Editors/High-Tech Writers

SUNNYVALE, Calif.--(BUSINESS WIRE)--Oct. 2, 2000

Oki Semiconductor, a leading manufacturer of advanced integrated circuit solutions for the wireless market, today announced the availability of a new low cost, low voltage linear Codec targeting the CDMA digital handset market.

The ML7041 sets a new standard for functionality by incorporating all major peripheral handset features, including speaker driver, tone generator and voice detection circuits. In addition, it enhances voice quality through 14-bit linear converter technology, and directly drives a dynamic speaker, thereby offering users a lower cost basis by maximizing board space.

Suitable for most cellular/PCS handsets, the ML7041 is compliant with the latest digital technologies including CDMA (IS-95) and TDMA (GSM and IS-54B).

By employing a DSP Codec architecture, the ML7041 improves both dynamic range and clarity improving voice quality. In addition, the device performs on-chip tone generation and voice detection -- a feature that will enable manufacturers and designers reduce handset size.

With board space a premium in any mobile handset platform, Oki integrated the key speaker amplifier in the ML7041 to provide a high quality, dynamic speaker with a maximum power (100 mW) voice signal.

"With the introduction of the ML7041, designers can now improve voice clarity while shrinking the design around a low 2.4 V IC. This new product defines a new class of energy-efficient Codec, providing unprecedented levels of flexibility and extended mobile air-time," said Scott Gardner, wireless products marketing manager for Oki Semiconductor. "This latest addition to Oki's broad line of wireless communications products demonstrates our ongoing commitment to introducing leading-edge products in this rapidly growing market segment."

Technical Information

The ML7041, a third generation Oki linear Codec, offers an improved feature set which incorporates a robust amplifier circuit capability on-chip to drive the latest cutting-edge, low impedance dynamic speakers commonly used in handsets. The Oki design team developed a special driver circuit architecture providing an incredible 100mW drive in a low impedence speaker. The ML7041 provides benefits such as lower cost since no external amplifiers are required, and the full-scale volume capability of the speaker is reached without clipping which improves the audio experience for the hearing impaired.

Power consumption, and its effect on airtime, is a common obstacle requiring special attention. The ML7041 design concept hinges on an advanced Oki 0.45 um double-poly CMOS process providing sufficiently low transistor threshold voltages to allow 2.4 V operation to maximize a handset's battery life.

The ML7041 applies an Oki application-specific DSP architecture to improve the filtering performance and generate telephony tones. Applying a small DSP core on-chip allows sigma-delta post-equalization processing, which improves signal-to-noise while lowering power consumption.

Oki's linear Codec provides a flexible user interface for two microphones, one headset, two general-purpose inputs and a speaker output with on-chip adjustable gain control. The ML7041 will unburden the external, baseband DSP engine by generating all common telephony tones such as DTMF, side, and information tones. An added feature, no longer requiring firmware support on the CDMA chipset, is a new integrated transmit voice detection scheme.

Other features include:

-- Wide voltage range (Vdd: 2.4 V to 3.3 V) for increased battery life

-- Selectable PCM u-law/PCM A-law/14-bit linear coding for flexibility

-- Linear signaling versus PCM encoding will save the embedded handset DSP at
least two MIPS

-- Built-in dual low-dropout regulators and four general-purpose drivers (150
mAx6) allow microphone, headset, hands-free accessory, and other connections.

-- Power down mode consumes only 3 uW typ, ensuring maximum battery life

-- I(2)C interfaces simplifies connection with popular processors

Packaging

The ML7041TB is available in 48-pin thin quad flat pack TQFP with tight 0.50 mm pin pitch. A ball grid array version (ML7041LA) will soon be available for high volume applications offering BGA48 (BGA48-P-56-0.65-K) with tight 0.65 mm pin pitch.

Pricing & Availability

Samples and production volumes of the ML7041 devices are available now. Pricing starts below $3.50 for TQFP48 (TQFP48-P-0707-050-K) version in 100K unit quantities. A smaller BGA version will be available within two months.

Oki's Telecom Products

Oki's Telecom Group offers a diverse range of integrated circuits targeting traditional and emerging data and voice communication applications. Products range from industry-leading, hands-free accessory system-on-chip (SOC) devices, with on-board Codecs and noise/echo cancellation DSP circuits, to CMOS baseband devices for personal wireless communications. A host of communication-centric applications are also supported including telecom infrastructure (POTS), wireless local loop, cellular handset, base stations and cordless.

About Oki Semiconductor

Building on Oki's century-long commitment to communications technologies and markets, Oki Semiconductor designs and markets a broad line of advanced integrated circuits for telecommunications, network, automotive, computer and consumer products. Oki's product lines include optical, telecommunications, speech synthesis, ASIC, microcontroller and memory devices, which are offered in a variety of creative packages. Founded in 1977 and headquartered in Sunnyvale, Calif., Oki Semiconductor is a division of Oki America Inc., which is a subsidiary of Oki Electric Industry Co, Ltd. Oki has ISO-9000-certified manufacturing facilities in Japan and Thailand. Information on Oki Semiconductor and its products is available through its Web site at http://www.okisemi.com.

Note to Editors: a product photo is available in the pressroom at www.okisemi.com.