Motorola proclaims advanced CMOS imaging sensor
Motorola proclaims advanced CMOS imaging sensor
George Kotelly
Manufacturers of small imaging products, such as digital cameras, camcorders, facsimile machines, PC cameras, and scanners, are incorporating advanced CMOS imaging technology to reduce manufacturing costs by at least 50%, add higher integration levels, and boost product functionality and quality. To meet these needs, Motorola (Chandler, AZ) has released a line of ImageMOS image-capture products--one of which it claims is the world`s first trilinear CMOS image sensor with an on-chip digital signal-processing engine.
In the first part of a multiphase rollout, Motorola has unveiled nine devices, including three image sensors, three image-capture engines, two video analog-to-digital converters, and a programmable timing generator, that all support both CCD- and CMOS-based image system designs. One image sensor chip, of major importance to imaging system designers, is the MCM20006, 300-dpi, trilinear image sensor/capture processing engine. It integrates a five-line, three-color, dual monochrome, 2752-pixel photo sensor; timing control; analog-processing chain; 10-bit A/D conversion, and I2C serial port programming control. Tight integration allows this single-chip sensor to replace as many as four parts typically required in systems using CCD sensors.
A major challenge in designing ICs for digital cameras and scanners is providing an architecture that reduces system costs. Says John Fairholme, director of Motorola Image Capture business, "By integrating vision capability with mainstream CMOS manufacturing, you create a totally integrated solution that combines analog and microprocessor technologies onto the sensor chip at an attractive price."
Compared to CCD or contact image-sensor-based designs, the line of Motorola CMOS sensors eliminates special-purpose timing chips and power supplies by using a single 3.3-V supply and CMOS-compatible I/O chips.
The sensors incorporate the Eastman Kodak (Rochester, NY) patented advanced CMOS Imager "pinned" photodiode design manufactured by the ImageMOS-enhanced CMOS process developed by Motorola. Color versions of the sensors incorporate a color filter array (CFA) using Kodak proprietary filter materials. Silicon and CFA processing are run on separate 8-in. wafer lines at Motorola`s MOS-12 site in Chandler, AZ. The resulting imager performance largely overcomes the noise-performance and color-response limitations associated with conventional CMOS sensors, while providing performance specifications that equal or exceed those of consumer-product CCDs currently on the market.
"Circuit price, performance, functionality, and power dissipation are important in consumer products such as cameras, but system-development tools, knowledge of the application, standards, and the ability to get to market quickly are also required," says Fairholme. "In announcing this family of devices, Motorola demonstrates its commitment to provide complete systems solutions to imaging markets," he says.
Application-development boards are available to support design-in of the sensors and digital image-capture engines. The trilinear image sensor with integrated capture processing engine in a 28-lead CDIP package sells for $19.50.
Says John Carey, Motorola manager of marketing communications, "This chip provides `on-the-fly programmability.` That is, you can program and optimize the sensor`s operation for different parameters, such as speed, resolution, and color sensitivity. By manipulating the image in faster time, you capture and display only the information you need, and at low power."
Adds Fairholme, "The sensor will find wide use in cameras first, then move into fingerprint and image-capture applications." He says that CMOS technology will add to market growth; it won`t replace the established CCD market. "CMOS will start at low-end applications as the prime target for CCD replacement," remarks Fairholme, "such as low-resolution security camera systems."