Cirrus Logic Inc., for one, will introduce an analog front-end interface chip next week that it hopes will open the market for low-cost digital cameras. Developed in conjunction with Polaroid Corp. and IBM Corp., the Crystal digital imaging chip provides a 13-bit A/D converter with correlated double sampler for CCD-based digital still cameras. Cirrus is promoting high image quality at low cost.

Significantly, Cirrus and partners IBM, which manufactures charge-coupled devices, and Polaroid, which designs them, have barnstormed Taiwan in hopes of encouraging Taiwanese manufacturers to enter the digital still camera market. The trio recently held design seminars there with Solomon, a Taiwanese components distributor. Also, digital camera designer Sound Vision (Framingham, Mass.) demonstrated a reference design in Taiwan using the Cirrus-IBM chip, said Doug Holberg, Cirrus' director of imaging and video products.

A Taiwanese entry into the market would mean price competition for Japanese manufacturers, he said, and could help lower prices for consumers. Holberg expects that within the next year, some vendor will produce a 2 million-pixel camera in the $200 to $300 range.

The worldwide market for digital still cameras is expected to reach $5.4 billion by 2002, according to a joint study by International Data Corp. (Framingham, Mass.) and Future Image (Burlingame, Calif.). The so-called "megapixel" segment (more properly, XGA cameras with 1.3 million pixels) is expected to account for 95 percent of this by next year.

But Will Strauss, principal analyst at Forward Concepts (Tempe, Ariz.), said that for the industry to achieve a compound annual growth that he sees at 42 percent by 2002, the price of a megapixel camera must hit $200 or less. Thus, the chip sets used-including CMOS or CCD sensors, signal conditioners, A/D converters, DSPs and microcontrollers-must drop from approximately $35 in 1997 to about $10 in 2002, said Strauss. Strauss believes that Sierra Imaging (Scotts Valley, Calif.) supplies the $45 chip set used in current-generation cameras from Olympus, Agfa and Pentax. Called Raptor, the chip set provides all the major functions needed to preview, capture, compress, store, transfer and display digital images.

The three-chip set includes Sierra Imaging's DSP ASIC, a SparcLite RISC processor (MB86831) and an 8-bit microcontroller (MB89165) from Fujitsu Microelectronics. An ARM core has recently displaced a SparcLite device as the central controller. Industry players are increasingly turning to partnerships to meet their goals in this evolving market. Besides the Cirrus-IBM-Polaroid alliance, Motorola's Semiconductor Products Sector (Austin) is partnering with Kodak on a range of products, from CMOS image sensors, to DSP elements. Similarly, LSI Logic Corp. (Milpitas, Calif.) and Minolta have partnered on a digital-camera design.

LSI's approach

LSI Logic's DCAM-101 is essentially a highly integrated JPEG compressor that contains all the major functions needed to preview, capture, compress, filter, store, transfer and display digital images. The device captures 3.3 million pixels/second (at 24 bits/pixel, 4:2:2 compression), and supports pixel resolutions up to 2,000 x 2,000. This would allow some video or motion JPEG capture at a rate of 11 JPEG images/second at VGA (640 x 480-pixel) resolution-a full 30 frames/second in the camera's LCD preview screen.

The DCAM-101 includes a MIPS RISC processor core, but requires an external sensor, sensor signal conditioning and A/D converter. This may be the gap that Cirrus hopes to fill with its high-resolution A/D converter, the CS7620. It uses a dynamic-range expansion technology, what Cirrus calls "DRX," to provide a larger word size for each pixel-up to 13 bits of intra-scene dynamic range. This is accomplished, said Holberg, with an analog gain-ranging amplifier to increase the signal-to-noise ratio of the CMOS device.

He maintained that the CS7620 can improve image clarity and details, as well as reduce system cost and boost camera performance. The company expects the $4 device to be available for volume production during the second quarter.

In the reference design to be built by Sound Vision, Cirrus' A/D will be paired with IBM's CCD sensors. These 0.5-micron pixel arrays with up to 2 million pixels are among the few CCDs manufactured on 8-inch wafers-a factor that may make them cost-competitive with CMOS imagers. A Sound Vision chip, the Clarity 2.0, will serve as the DSP controller, said Holberg.

The famous Clarity 1.0 reference camera design built and marketed by Sound Vision utilized a Texas Instruments Inc. TMS320C206 DSP, along with an 800,000-pixel (1,000 x 800) CMOS sensor, 10-bit A/D converter, the Clarity 1.0 digital ASIC and 4 Mbytes of non-volatile memory. (Another 1 Mbyte of DRAM serves as a buffer, and an IGBT device controls the flash bulb.)

That reference design was the basis of Sound Vision's SVmini-209 CMOS digital camera. While a studio version sells for over $2,000, Sound Vision claims a reference design for consumer cameras has a $100 bill of materials.