HIGH-SPEED SAMPLING STRUCTURE FOR CCD IMAGE SIGNAL

摘要

A high speed correlated double sampling structure of a CCD image signal is provided to remove uncertainty due to a process of a sampling clock and a change of voltage supply and temperature variation, thereby realizing high speed sampling. A clock correction unit(50) moves a level of a clock inputted from the outside and buffers. A clock correction unit outputs a clock having the same phase of the input by offsetting a delay time caused during the level movement or the buffering process by negative delay. A correlated double sampling unit(20) samples the reference signal and an analog image signal of a CCD image sensor by using a clock provided from the clock correction unit. And the correlated double sampling unit obtains the difference of two sampling signals. A variable gain unit amplifies a signal provided from the correlated double sampling unit.