Solid-state linear X-ray sensors are used to produce high-quality X-ray digital images. A better understanding of effects observed in the different parts of this detector (scintillator, photodiodes, CCD shift registers, signal equalization function including ADC) can be reached by a more comprehensive understanding of how signals are generated in the devices. Behavioural models suitable for computer-aided analysis of each part of X-ray sensors are developed. The models, written in HDL-A (hardware description language dedicated to behavioural description of analog and mixed-signal systems), can be associated with circuit-level models already available for electronic components to provide a time domain simulation of an entire X-ray computed imaging system in a mixed-signal simulation environment.