Charged-coupled device signal processing models and comparisons

CCD signal processing schemes attempt to reduce the effect of (KTC), 1/f, and broadband noise on the output signal. A number of schemes have been reported over the years. These schemes employ time delay and subtraction to eliminate KTC noise and attenuate 1/f noise. They also include a low-pass function to reduce the effect of broadband noise. Signal processing schemes include dual-slope integration, correlated-double sampling, a variation of correlated-double sampling referred to as switched-exponential filtering, and transversal filters. Signal processing that does not use delay and subtraction to eliminate KTC noise is also discussed. A consistent technique is used to analyze the various processing schemes. Transfer functions for signal and noise are presented for each. Performance comparisons are given with emphasis on their applicability to relatively high speed CCD readout applications (readout rates of 1 Mpizel/s and faster).