IC Performs All Functions Of High-End Color Scanner

All the functions of a high-performance color scanner, including analog front end, sensor clock generation, microstepping motor control, data buffering, and parallel port interface, are all provided by the LM9830, a 36-bit color document scanner IC. Using a 6-MHz, 12-bit A/D converter with pipelined architecture, the chip operates at a conversion rate of 6 Mpixels/s and scans images in full 36-bit color. It incorporates digital offset and shading correction, as well as all analog processing functions built into the firm's earlier imaging ICs. These include gain offset and correlated double sampling.In addition, digital pixel processing and individual RGB gamma tables enable the IC to provide horizontal resolutions from 50 to 600 dpi. Vertical resolutions also range from 50 to 600 dpi in 1-dpi increments.The chip also offers fine control over two clock rates, which allows matching the scanner clock rate to the parallel-port interface speed. The result is scan speeds that are as much as four times faster than current parallel scanners.