Furthermore, the MLX75307 offers a wide dynamic range of 190 dB for multi-scene conditions (110 dB for intra-scene conditions) and resolution of 750 by 400 pixels. Its signal-to-noise ratio is 102 dB and operating voltage is 3.3 V. Operating temperature ranges from –40°C to 125°C. Melexis characterized the device according to the European Machine Vision Association (EMVA) 1288 standard.
STMicroelectronics’ VL5510 automotive CMOS imager also suits ADAS applications. It features a 1024- by 512-pixel format, 7.14-V/lux sensitivity, 5.6- by 5.6-µm pixel size, 33-aA/pixel low dark current (at 25°C), 34-frames/s frame rate, and high quantum efficiency at near-infrared wavelengths. The processor complements a dedicated vision processor developed by the company in collaboration with Mobileye.
Sensata Technologies offers a CMOS imager, the Avocet, for ADAS applications with an enhanced dynamic range and excellent sensitivity for low-light and night-to-bright daylight driving conditions. It features a 154-dB dynamic range and comes in RGB or RGBi versions that feature the company’s Autobrite widedynamic- range technology, which was acquired from Cypress Semiconductor.
After nearly a decade of research, the Swiss Center for Electronics and Microtechnology (CSEM) discussed a smart CMOS image sensor design at this year’s ISSCC. Aimed at lowering the cost of automotive, industrial, and consumer electronics applications, the Icycam imager integrates a DSP chip with a CMOS sensor on a single die. It features QVGA resolution (320 by 240 pixels) and a digital logarithmic image compressor.
MEDICAL APPLICATIONS ARE HERE
CMOS imagers together with powerful image processors have made significant contributions to the medical field. These combined devices are finding their way into imaging applications, diagnostic probes, swallowable pills, and a host of other applications (see “The Pulse Quickens For Cutting-Edge Medical Electronics Advances”).
For example, they’re enabling disposable diagnostic instruments such as endoscopes, like those from Micro-Imaging Solutions (Fig. 4). The company offers a complete CMOS-based camera system on a postage-stamp-sized circuit board. The camera-on-a-chip design is manufactured by several CMOS camera companies.
Micro-Imaging Solutions is concentrating on placing the video processing as well as most of the timing and control circuitry away from the pixel array plane. The whole idea is to minimize the size of the imager array. The circuitry can be stacked directly behind the imager plane or placed several meters away and connected to the imager via an RF or a disconnectable cable link.
Analog Devices offers a pair of powerful, highly integrated, 14-bit image processors for CMOS and CCD sensors. The dual-channel ADD9978A and quad-channel ADD17004 deliver a high degree of clarity, visualization, and accuracy in 75-MHz digital still and videocamera designs for medical and industrial machine-vision applications.
THE NEXT GENERATION
Beyond the realm of CMOS and CCD image sensors, SiOnyx Inc. is developing a new material called “black silicon.” The company believes the material will lead to a new class of image sensors that are 100 times more sensitive than conventional silicon, detect energy from the ultraviolet to the short-wave infrared bands, operate at very low voltage levels, and can be made in extremely thin 0.5-µm forms (Fig. 5). Most importantly, the material is compatible with existing CMOS processing methods.
“This is a brand new material that is compatible with the largest manufacturing infrastructure of the world,” says Stephen Saylor, SiOnyx’s president and CEO.
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