XPS: a multi-channel preamplifier-shaper IC for X-ray spectroscopy

• Published in: IEEE transactions on nuclear science 1998-06, Vol.45 (3), p.732-734
• Main Authors: Krieger, B., Kipnis, I., Ludewigt, B.A.
• Format: Article
• Language: English
• Subjects: CMOS technology; Integrated circuit noise; Noise shaping; Preamplifiers; Pulse amplifiers; Pulse shaping methods; Spectroscopy; Synchrotrons; X-ray detection; X-ray detectors
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/23.682625

An integrated circuit featuring 48 channels of charge sensitive preamplifiers followed by variable-gain pulse shaping amplifiers is being developed as part of an X-ray spectrometer with a highly segmented detector to handle high fluxes in synchrotron experiments. Such detector systems can provide excellent energy resolution combined with one-dimensional spatial information. The IC combines many basic spectroscopy amplifier functions with a low noise preamplifier section to produce a unique circuit capable of driving conventional ADC modules directly. An important feature of the design is the novel CR-RC/sup 2/ pulse shaper. In this section, high-linearity transconductor circuits are required in order to provide a broad range of continuously variable peaking times while still maintaining the linearity and noise performance necessary for X-ray spectroscopy. Reported here are first measurements made on the performance of a 16-channel prototype integrated circuit. At present, the preamplifier-shaper circuit achieves an equivalent input noise of 26 electrons RMS at 2 /spl mu/s peaking time with a 0.2 pF external capacitor, which is similar to the capacitance of a single detector element. The design was fabricated in standard 1.2 /spl mu/m CMOS technology.