A fast current readout strategy for the XFEL DePFET detector

In this paper, we propose a novel architecture to implement the current readout of DePFET Active Pixel Sensor (APS) matrices to be used in experiments at the European X-ray Free Electron Laser (XFEL). The circuit performs a fast trapezoidal filtering of the DePFET signal with a very simple architecture based on a Flip Capacitor Filter solution. We discuss the possible available trade-offs between noise and speed performances based on three different timing strategies that can be used to readout the DePFET matrix. Simulation results are shown for a first design of the circuit and expected noise performances are discussed in the last part of the paper.