Spectroscopic performances of DePMOS detector/amplifier device with respect to different filtering techniques and operating conditions

DePMOS structure provides detection and amplification jointly and it is free of interconnection stray capacitance. An electrical model of the device has been provided. The most relevant parameters have been measured in order to choose an adequate readout electronics, to fully exploit the intrinsic low noise of the device. DePMOS can operate in continuous mode, i.e. without applying any clear pulse during the signal processing, and can be read out by a time continuous shaper amplifier. An unequalled noise of 2.2 electrons r.m.s. at room temperature has been measured. In this mode DePMOS can be used e.g. as the readout device for silicon drift detectors. DePMOS was developed to be the basic element of an active pixel sensor suitable to cope with the requirements of XEUS wide field imager. In a matrix arrangement, each pixel must be read out by a time variant filter. A multichannel integrated shaping amplifier, based on multi correlated double sampling, has been designed. Spectroscopic resolution obtained filtering the pixel matrix with this readout chip is in agreement with measurements in continuous mode and matches the predictions of the model presented. It has also been experimentally proved that the clear procedure doesn\´t introduce additional noise contribution, even in the very low noise range achieved. This qualifies DePMOS as a "reset-noise-free" device.