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

Diffraction-limited storage rings are posing huge challenges to 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 designs. The proposed readout channel, prototype fast readout channel for ptychography applications (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 65-nm CMOS technology and features single photon resolution at 5-, 9-, 18-, and 25-keV photon energies, a power consumption of $220~\mu $ W, and a pixel area of $150\times 150~\mu $ m2. It also offers a 2-bit switchable peaking time selection for signal-to-noise ratio optimization, signal-over-threshold (SOT) identification for zero-suppression, and 10-bit analog-to-digital conversion per channel. In the present work, an overview of the readout channel architecture will be given, and results from the characterization of the charge sensitive amplifier (CSA) and the shaper employed in the architecture will be provided, in addition to the noise performance of the pFREYA channel.