"CUBE", A low-noise CMOS preamplifier as alternative to JFET front-end for high-count rate spectroscopy

• Published in: 2011 IEEE Nuclear Science Symposium Conference Record pp. 1972 - 1975
• Main Authors: Bombelli, L., Fiorini, C., Frizzi, T., Alberti, R., Longoni, A.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.10.2011
• Subjects: CMOS integrated circuits; CMOS technology; Ions; JFETs; Single photon emission computed tomography; Spectroscopy
• ISBN: 1467301183; 9781467301183
• ISSN: 1082-3654
• DOI: 10.1109/NSSMIC.2011.6154396

We present a monolithic CMOS charge preamplifier named "CUBE". It is specifically designed to be used with Silicon Drift Detectors (SDD). We will show that the use a MOSFET as input transistor allows superior noise performances at very short shaping times respect to the state-of-the-art externally connected JFET devices. We will show the achievable energy resolutions using a 10mm 2 reference SDD with different count-rates and with different analog and digital commercial filters. A state-of-the-art energy resolution (for a silicon detector) of 125 eV at 6 keV has been achieved with the optimum shaping time. Moreover, it will be shown that CUBE enables the use of an extremely fast-peaking time of only 100 ns with extraordinary good energy resolution of 149 eV. As a consequence we can state that, the CUBE preamplifier is very well suited for high count-rate spectroscopy applications. An example of the performance with output countrate up to 490 kcps will be reported.