Transient numerical analysis of electrical signal injection into the surface charge-coupled device (CCD) is given regarding the potential equilibration method. The analysis is composed of the charging and discharging processes of signal charges, characterized by time intervals T
Cand T
Dof the respective input pulses. A concept of "setting time T
S" explains how the mode of injection converts from the potential equilibration to dynamic injection, and determines an optimum T
C. A concept of "residual effect of excess charges" is discussed in relation to sampling effect. The procedure to determine an optimum T
Dis also proposed. The optimum input timing is divided into two instances in accordance with the degree of the gate length

µm. For the instances (

µm) the timing condition is further split into two cases, depending on the biased potential difference

. The above conclusions can be applied to setting input pulses and the structure of CCD inputs designed for analog signal processing.