Abstract Charge sensitive amplifiers (CSA) form the first stage of most detector readout circuits. The operating range of the readout circuits depends on the saturation limits of the Charge sensitive amplifiers, thereby limiting the range of the detector system as well. A number of methods have been introduced to extend the dynamic range of the readout circuits. The Boston Extended Range Amplitude integrated circuit, BEAR 1, uses two switchable capacitors, which when added in parallel to the detector, shares the deposited charge and prevents the circuit from saturating. This article describes the design, simulation, fabrication and experimental results of a new version of this integrated circuit (IC), called BEAR 2. BEAR 2 has new features, mainly adjustable thresholds and variable energy ranges using different switchable capacitor values. Experimental results indicate that BEAR 2 can measure input energies from 6 MeV to 4.7 GeV with a resolution dE/E of about 7.1 with switchable capacitors of 1 and 20 nF. At 11.4 mW and with analog to digital converter clock speeds as high as 5 MHz, BEAR 2 is a low power, high speed, single channel readout circuit that can be used with detector systems like energetic particle telescopes. This has applications for a number of areas including high energy radiation belt physics, cosmic rays as well as Solar Energetic Particle (SEP) physics.
Gomez et al. (Thu,) studied this question.