Affiliation: | aInstitute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 229-8510, Japan bDepartment of Physics, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan cAcrorad Co., Ltd., Uruma, Okinawa 904-2234, Japan |
Abstract: | This paper describes the recent development of a low-noise analog front-end ASIC for CdTe detectors. The ASIC is designed on the basis of the Open-IP LSI project led by JAXA and implemented using TSMC 0.35-μm CMOS technology. The ASIC contains eight identical channels, each of which includes a charge-sensitive amplifier, band-pass filters, and a sample-and-hold circuit. Preliminary testing of the ASIC achieved noise performance of 188e-+7.5e-/pF. In order to verify the low-noise characteristics, the ASIC was connected to a guard-ring-equipped CdTe diode detector with dimensions of and having a thickness of 0.5 mm. As a result, the gamma-ray spectra of radioactive sources were obtained with good energy resolutions of 2.51 and 2.35 keV (FWHM) for gamma rays of 59.5 and 122 keV, respectively, at room temperature. |