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.