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The results of the simulation the influence of the proton flux on the electrical characteristics of the device structure of dual-channel high electron mobility field effect transistor based on GaAs are presented. The dependences of the drain current ID and cut-off voltage on the fluence value and proton energy, as well as on the ambient temperature are shown.

The aim of the work is analyzing the results of an experimental research of a charge-sensitive amplifier with an adjustable conversion coefficient and a base level recovery circuit fabricated on the master slice array MN2XA030 for silicon photomultiplier tubes. The amplifier is called ADPreampl3. The parameters were measured on a small batch of chips in the amount of 20 samples. In the process of measuring the main parameters of the amplifier, the signal from the SiPM Photonique equivalent circuit was fed to the amplifier input. In the course of measuring the parameters, it was revealed that the spread of the baseline level for the FOut output ranged from -24 to 276 mV with an average value of 85.6 mV. In this case, a voltage changing in the FOoutShift node from -3 to 3 V is sufficient to establish a base level value of FOut output close to zero. When the recovery scheme is disabled, the spread of the basic level for OutA output is from 300 to 800 mV. When the OutAShift output is connected to the zero-voltage bus the average base level for OutA output is 3.72 mV and for OutAinv output it is minus 2.42 mV. The base level at the outputs OutA and OutAinv smoothly changes in the range of ± 0.9 V. At maximum gain, the dynamic range of ADPreampl3 exceeds 20 dB, however, at the same time, the conversion coefficient depends on the value of the input charge. To register large input charges, it is recommended to reduce the output pulse by reducing the voltage at the Gain pin or process the signal from the FOut pin. The output parameters of the experimental samples are compared with the results of computer simulation. The discrepancy between the results of modeling and measurements, peak time and propagation delays of the amplifier signal was revealed. Based on this, a decision to adjust the SPICE parameters of the elements used in the simulation was made.

The implementation of a charge-sensitive amplifier (CSA) based on the МН2ХА030 array chip (AC) with an adjustable conversion factor for processing signals of silicone photomultipliers (SPM) is considered. The developed CSA, named ADPreampl3, contains a fast and slow signal circuit (SC). The fast SC includes a transresistive amplifier-shaper with a base-level adjustment circuit, and a slow SC includes an CSA, a shaper, and a base-level restorer (BLR) circuit. The main advantage of ADPreampl3 amplifier when used in multichannel integrated circuits is the minimum number of elements used, due to the use of the same stages to perform different functions. To correctly simulate the operation of ADPreampl3, taking into account the features of the input signal source, a simplified electrical equivalent circuit of the SPM, applicable to both circuit simulation and measurements, is proposed. Circuit simulation of ADPreampl3 using the proposed equivalent circuit of SPM with a supply voltage of ±3 V, made possible to establish that: fast SC is characterized by the bandwidth up to 60 MHz and allows adjusting the base level in the range from -0.1 V to 0.2 V. Thus, it is possible to compensate the technological variation of the output voltage of the fast SC or set the required switching threshold of the comparator connected to the output of the fast SC; slow SC allows you to adjust the base level in the range from -1 V to 1 V and smoothly change the amplitude of the output signal, including phase inversion, when the control voltage changes from -1 V to 1 V; the BLR circuit provides a constant shape of the output voltage pulse with a DC input current of ADPreampl3, varying in the range of ±190 μA, and a negligible change of the base level at ±20% of the resistance variation of integrated resistors. ADPreampl3 amplifier enables the transition to the ``sleep'' mode with a decrease in current consumption up to 10 μA, maintains operability at an absorbed dose of gamma radiation up to 500 krad and the effect of the integral neutron fluence up to 1013 n/cm2 and can be used in multi-channel signal processing chips of SPM.