A complete mixed-signal processing IC that provides 3-channel CCD (charge-coupled device) or CIS (contact image sensor) signal conditioning and 12-bit A/D conversion has been developed for use in scanner applications, such as flatbed and PC scanners. The VSP3000 chip provides the required 2-MHz power per channel needed for 3-channel video signal processing. Each channel contains sensor signal sampling, black-level adjustment, and a programmable gain amplifier to maintain optimum input signal levels. The ability to vary the gain of the input signal compensates for varying background light conditions. The IC also includes three correlated double samplers for extracting the pixel amplitude information from the noise, which results in better image quality. The device also features integrated triple-correlated double sampler, 3-channel (6 MHz) color mode, 0 dB to 13 dB analog programmable gain amplifier, internal voltage reference, 3V/5V digital I/O compatibility, low power dissipation (400 mW), and guaranteed no missing codes. Operation is from 0°C to 85°C from a 5V supply.
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