A preamplifier with digital output for semiconductor detectors

A new topology for a front-end preamplifier for semiconductor detectors with digital output has been developed. The preamplifier outputs a frequency-modulated pulse train that can provide information both on the input pulse rise time and on the total charge collected from the detector. This type of preamplifier is very well suited to CdZnTe detectors, allowing for pulse shape discrimination and correction without the extra electronics required by the conventional approach. The circuit was implemented, performing in accordance with the theoretical predictions, and its noise analysis developed with a view to optimize its performance.