An integrated low-noise charge-sensitive preamplifier with virtually unlimited spectroscopic dynamic range

A low-noise ASIC preamplifier for semiconductor detectors has been built and characterized, which is able to provide a linear spectroscopic measurement of the detector charge signals even when its output voltage is saturated. The preamplifier works in a conventional mode, i.e. as an active current integrator, when the output signal is below a preset threshold. If the signal is larger the preamplifier operates in a non-standard controlled fast-reset mode, which is effective in providing a linear measurement of the detector signal charge even when the preamplifier works close to or in saturation. The experimental relation between the measurement and the input charge keeps perfectly linear irrespective of the non-linearity of the preamplifier working regime, which yields a dynamic-range boost of more than one order of magnitude.