Analog Readout Channel for Continuous-Wave X-Ray Science Applications

Diffraction-limited storage rings are posing huge challenges on the detectors required in new generation x-ray experiments, especially those based on continuous-wave operation. A modern mixed-signal readout channel demands strict requirements on noise, power consumption, and frame rate, asking for advancements in both analog and digital design. The proposed readout channel, pFREYA, is designed for pixellated detectors to be employed in continuous-wave x-ray science applications (e.g., ptychography) with a frame rate of 1 MHz. It is developed in a commercial 65nm CMOS technology and features single photon resolution at 5 keV, 9 keV, 18 keV, and 25 keV photon energies, a power consumption of 220 μW, and a pixel area of 150μm× 150 μm. It also offers a 2-bit switchable peaking time selection for signal-to-noise ratio optimisation, signal-over-threshold identification for zero-suppression, and 10-bit analogto- digital conversion per channel. In the present work an overview on the readout channel architecture will be given and results from the characterisation of the CSA and the shaper employed in the architecture will be provided, in addition to the noise performance of the pFREYA channel.