Shaping circuit for improving linearity, bandwidth, and dynamic range in ToT-based detectors

The quantitative measurement of energy deposits in particle detectors, particularly in calorimeters, is usually accomplished with the help of Analog-to-Digital converters (ADCs) due to their precision, wide measurement range, and good linearity. However, drawbacks such as power consumption, data volume, and bandwidth limit their use in the next generation of high-energy physics experiments. Time-over-threshold (ToT) systems offer simplicity, low power consumption, ease of integration, and a wide bandwidth, but they lack precision, linearity, and dynamic range. In this work, we propose a shaper circuit that improves the weaknesses of ToT systems without sacrificing performance. The shaper contains a fast diode that discharges a capacitor with a constant current, thereby linearizing the trailing edge of the input signal. The three tested capacitances (47 pF, 100 pF, and 330 pF) probed the linearization concept with R-squared values between the linear model and the data around 0.99. The shaper precision and resolution improve by increasing the capacitance, but also the dead time. The shaper bandwidth was ∼ 150 MHz for 47 pF. We simulated and implemented the shaper concept in the readout system of the Ring Imaging Cherenkov detector of the Compressed Baryonic Matter experiment at FAIR. • A conditioning circuit to improve the bandwidth, linearity, and dynamic range of particle detector readouts based on Time-over-Threshold. • Validation of the proposed concept by implementing it in the readout electronics of the Ring Imaging Cherenkov detector of the Compressed Baryonic Matter experiment. • The simplicity of the proposed concept reduces power consumption and improves the integrability of the circuit per channel, enhancing its implementation in Application Specific Integrated Circuits (ASICs) for particle detectors.