Analog Devices consumer digital-imaging converters optimized for professional applications

NOVEMBER 27--Analog Devices Inc. (Norwood, MA; www.analog.com/AD9821) has expanded its data-converter portfolio with the addition of two state-of-the-art
analog front-end (AFE) converters for digital imaging. Analog Devices AFEs are used in many high-performance digital still cameras and camcorders. The company now offers devices for CMOS and CCD imaging sensors used in high-end digital still cameras and camcorders and in high-performance scientific and industrial imaging applications, such as machine vision, biomedical imaging, and crash-test analysis.

The AD9821 is designed to interface with CMOS imagers used in applications for which image quality is essential, such as medical imaging, microscopy, industrial/machine vision, digital photography, biometrics, and automatic inspection equipment. An alternative to component-based solutions using several ICs performing discrete functions, the AD9821 provides all the functionality needed to digitize an image from a CMOS image sensor on a single, integrated chip. It features a 12-bit, 40-MSPS ADC that interfaces with high-speed CMOS sensors via a differential sensor input and includes a low-noise optical black clamp and a 0- to 36-dB, 10-bit programmable gain amplifier. The AD9821 dissipates only 150 mW, enabling longer battery life in portable applications.

The AD9845B includes a 12-bit, 30-MSPS analog-to-digital converter, a 30-MSPS correlated double sampler, a 4-dB±6 dB 6-bit PxGA, and a 2- to 36-dB 10-bit variable gain amplifier. It also provides an input clamp, black-level clamp, and input modes for processing analog video signals. Its internal registers are programmed through a three-wire serial digital interface. Programmable features include gain adjustment, black-level adjustment, input confirmation, and power-down modes. The AD9845B operates from a single 3-V power supply and typically dissipates 153 mW.