A Multispectral Analog Photon-Counting Readout Circuit for X-ray Hybrid Pixel Detectors

摘要

In this paper, an all-analog pixel architecture for the readout of X-ray pixel detectors with multiple energy discrimination is proposed. The circuit comprises a self-triggered reset charge amplifier and three distinct channels devoted to the detection on a specific energy band. Each channel is composed of an autocalibrated comparator, an energy window identification logic, and an analog counter with an adjustable dynamic range. A test prototype has been implemented with a standard complementary metal–oxide–semiconductor 0.35- $muhbox{m}$ technology. The pixel circuitry dissipates 15 $muhbox{W}$ at 3.3 V, has a noise equivalent charge of 82 $hbox{e}_{rm rms}^{-}$ at 200 fF, and allows, on each of the three channels, a dynamic range that exceeds 12 bits. The designed pixel is a square with a 109- $muhbox{m}$ pitch.