Characterization of front-end read-out electronics of thin-film on ASIC

Different front-end read-out electronics of thin-film amorphous silicon based photodetectors deposited on ASIC were characterized and mutually compared. To provide equal conditions actual signals from a p-i-n photodiode were simulate. A protection structure, which was applied in all read-out circuits, was characterized first. Then we measured and compared the transfer characteristics, linearity, dynamic range, detectivity and noise properties of three read-out circuits: a current-to-frequency converter, a current-to-voltage converter and a /spl Sigma/-/spl Delta/ analog-to-digital converter. The current-to-frequency converter is most appropriate for a small embedded system based on a microcontroller due to its simplicity and sufficient electronic properties.