Signal conditioning circuit between a-Si:H p-i-n photodetector and A/D converter

A CMOS charge-to-voltage converting circuit is designed. This circuit works with a hydrogenated amorphous silicon (a-SiH) p-i-n photodetector in either dc bias mode or charge- storage mode, converts the photo-charge of the detector into a voltage with a high linearity at 10 MHz, and eliminates the effect of the dark current. The modeling of the a-Si:H p-i-n photodetector in the two working modes is implemented using SPICE switches.