VHDL-AMS modeling and simulation of a passive pixel sensor in a-Si:H technology for medical imaging

A VHDL-AMS model of a passive pixel sensor (PPS) for large area digital imaging is presented based on a highly accurate model for the leakage regime of an a-Si:H TFT. We consider, as examples, various diagnostic medical imaging modalities, whose requirements are translated into PPS circuit parameters such as pixel capacitance and input charge. Selected simulation results are presented which illustrate sensor output linearity, pixel readout time as well as the effect of pixel and integration capacitor sizes on output rise time. The flexibility and speed of the presented VHDL-AMS models can expedite accurate simulations for the design of large area digital imaging PPS arrays