Evaluation of the spectroscopic performance of the integrated multi-channel charge-sensitive preamplifier of TRACE with a silicon detector prototype

Secci

Pullia

2023

IEEE Trans. Nucl. Sci.

Self Cite

In this work both a theoretical study and experimental measurements are shown to describe the ENC (Equivalent Noise Charge) contribution of the parallel √ f noise of a chargesensitive pre-amplifier in a nuclear spectroscopic chain. Previous works have demonstrated that this noise is produced by the distributed capacitive coupling to bulk of the preamplifiers' highvalued feedback resistors, which give rise to a R-C structure known in literature as "diffusive line". The introduced noise is particularly evident when such devices are integrated in a chip using a polysilicon layer that has intrinsically high distributed capacitance to the chip's bulk. Different shaping amplifiers are taken into consideration (analog quasi-Gaussian, digital trapezoidal/triangular, CR-RC n ) and closed-form expressions of noise coefficients are given whenever possible.

Section: Experimental Verificationmentioning

confidence: 86%

Equivalent Noise Charge Contribution of the √f Parallel Noise in Nuclear Spectroscopic Measurements Using Different Shaping Amplifiers

Secci

Pullia

2023

IEEE Trans. Nucl. Sci.

Self Cite

“…The main feature of the device described in this work is its ability to swiftly recover a charge-sensitive preamplifier in case of saturation, producing at the same time an analogue signal that contains the information about the charge released by the detector. This technique, called "fast-reset", is based on the charge conservation principle and is well described in literature [5][6][7][8][9].…”

Section: Circuit Descriptionmentioning

confidence: 99%

Experimental performance of a highly-innovative low-noise charge-sensitive preamplifier with integrated range-booster

Pullia

2018

J. Inst.

Integrated charge-sensitive preamplifiers suffer from a reduced available dynamic range respect to discrete-type equivalents. This is due to the limits on maximum supply voltages that modern scaled technologies can tolerate. In this work we present a low-noise low-power integrated charge-sensitive preamplifier (CSP) for solid-state detectors. This device is equipped with an integrated range-booster that can enhance the spectroscopic range of the preamplifier by more than one order of magnitude, enabling high-resolution spectroscopy even if the preamplifier is in deep saturation condition. If the input signals from the detector are under the natural saturation threshold (40 MeV), the preamplifier works in an usual linear way, producing at the output the typical exponential signals. With proper filtering a resolution of approximately 1 keV is achievable. When a large signal from the detector saturates the preamplifier, a sensing circuit detects the saturation and switches the operation mode of the CSP to the "fast-reset mode". In this mode a constant and controlled current generator discharges the input node of the preamplifier until the normal operating point is reached. Meanwhile an auxiliary circuit similar to a TAC (Time-to-Amplitude converter) retrieves the energy of the signal that caused saturation. Although the natural dynamic range of the CSP is 40 MeV, the fast-reset mode enables for high-resolution spectroscopy (under 0.2% FWHM) up to several hundreds of MeV (700 MeV typically). One issue in this kind of circuits is the dependence of the energy measured with the TAC circuit on the baseline value of the CSP before the "fast-reset event" [5]. As a solution to this problem we propose a correction algorithm implemented inside the TAC block in the form of an analog circuit. On a test-bench a series of large 3 pC charge signals is injected in the input node of the preamplifier through a test capacitor. Before these events, residual charges ranging from 0 to 0.56 pC produce non-zero baseline voltages at the output of the CSP. The TAC with correction not only retrieves correctly the energy of the main event, but also rejects the baseline voltages, leaving the energy measurement unaffected. The fluctuations of the flat-top voltage in the signals produced by the auxiliary TAC circuit due to the different baseline voltages are under the 0.6% of the total signal amplitude.

Performance of the new integrated front-end electronics of the TRACE array commissioned with an early silicon detector prototype

Nuclear Instruments and Methods in Physics Research Section A:

Mengoni

Dueñas

et al. 2019

The spectroscopic performances of the new integrated ASIC (Application-Specific Integrated Circuit) preamplifiers for highly segmented silicon detectors have been evaluated with an early silicon detector prototype of the TRacking Array for light Charged Ejectiles (TRACE). The ASICS were mounted on a custom-designed PCB (Printed Circuit Board) and the detector plugged on it. Energy resolution tests, performed on the same detector before and after irradiation, yielded a resolution of 21 keV and 33 keV FWHM respectively. The output signals were acquired with an array of commercial 100-MHz 14-bit digitizers. The preamplifier chip is equipped with an innovative Fast-Reset device that has two functions: it reduces dramatically the dead time of the preamplifier in case of saturation (from milliseconds to microseconds) and extends the spectroscopic dynamic range of the preamplifier by more than one order of magnitude. Other key points of the device are the low noise and the wide bandwidth.