Design and Experimental Results of the BEAR Integrated Circuit for Energetic Particle Detection

Modern solid state detector readout circuits are limited by the operating range of the first stage charge sensitive amplifier or CSA. This in turn limits the energy range of systems using solid state detectors. Such systems are used in a variety of applications ranging from measuring solar energetic particles in space to use in medical devices on Earth. The current paper provides a novel solution implemented in the Boston Extended Amplitude Range (BEAR) integrated circuit. BEAR uses a CSA with two switchable capacitors to increase the range of the amplifier by 2 orders of magnitude higher than traditional CSAs. In this model the capacitors are dynamically switched in at set thresholds and are added in parallel to the detector to share the input charge. The integrated circuit (IC) has been fabricated and evaluated. Here we provide simulation and experimental results which demonstrate performance over measured signals from particles with energies from 1.4 MeV to 1 GeV with an average dE/E of 41%. Detector systems could measure a wide range of energetic particles when used with BEAR ICs.