A Multi-Spectral Analog Photon Counting Readout Circuit for X-Ray Hybrid Pixel Detectors

In this paper an all-analog pixel architecture for the readout of X-ray pixel detectors is proposed, comprising a self-triggered reset charge amplifier, three autocalibrated comparators, an energy window identification logic and three analog counters with adjustable dynamic range. A prototype has been built with a standard CMOS 0.35 mum technology: the pixel pitch is 109 mum, dissipates 15 muW at 3.3 V supply, has a noise equivalent charge of 82e
_rms

^-
at 200 fF and allows on each of the three channels a dynamic-range that exceeds 12-bit