W6662CF

Preliminary W6662CF SCANNER ANALOG FRONT END 1. GENERAL DESCRIPTION The W6662 is a highly integrated CCD/CIS analog front end signal processor. It provides the components required for all necessary front-end signal process of a CCD/CIS scanner, including a 3channel input clamp circuit for correlated double sampling (short as CDS) mode, a multiplexer to mux 3-channel inputs to a correlated double sampling (CDS) circuit, a programmable offset adjusted and gain controlled amplifier, a 12-bit analog-to-digital converter. CDS or S&H (sample and hold) of operation modes can be chosen. The device configuration is programmed via 3-wire or 4-wired interface, operation modes, offset and gain value of each channel can be programmed. 2. FEATURES 12-bit A/D Converter No Missing Code Guaranteed Three channels analog input with clamp circuit individually Integrated Correlated Double Sampler (CDS) Supports Contact Image Sensors (CIS) Accept CCD/CIS sensor with three channel or single channel analog out External offset voltage input for CIS reference voltage Built-in bandgap reference circuit for CDS mode and A/D Converter Integrated 6-bit Programmable Gain Amplifier (PGA) with 3-channel register selected Integrated 8-bit offset adjustment with 3-channel register selected 3 MHz sampling rate of offset/gain adjustment circuit Three-wired or four-wired Serial Interface programmable Registers readback capability Low power CMOS device Power down mode supported 3/5V...