Fast DEPFET current readout for X-ray astronomy missions

The DEPFET-based Active Pixel Sensor (APS) matrix is a new detector concept for X-ray imaging and spectroscopy applications. This type of detector can provide excellent energy resolution and high-speed readout. Both of these features, along with the advantage of random pixel accessibility, can fulfill the requirements of new imaging applications in the X-ray band. In a matrix arrangement, each pixel must be read out by a time-variant filter, so a proper multi-channel integrated filtering amplifier is needed. To operate large area matrices at very fast processing times, we have recently proposed a current readout configuration. In this paper, we explore the performance offered by this circuit when operated with a DEPFET matrix, specifically concerning its ultimate speed capabilities and the trade-off achieved between electronics noise and processing time.