A Low-Noise Readout Channel for X-Ray Ptychography Applications

In the present work, the design of a readout channel for a pixelated detector to be employed in X-ray ptychography is proposed and discussed. The channel is developed in a commercial 65 nm CMOS technology, features single photon detection at 5 keV, 9 keV, and 25 keV photons, with a noise of 250 e
^-
rms, a power consumption of 220 µW, and fits in an area of 150 µm × 150 µm. The readout channel is the elementary cell of an envisioned 128-by-128 pixel matrix and it is designed for operation at a 1 MHz conversion rate. A prototype 8-by-2 matrix, included in the pFREYA16 ASIC, was submitted to foundry to prove the feasibility of such detector. Preliminary noise evaluations, design considerations and post-layout simulation of a single pixel will be presented in this paper.