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One of directions of improving parameters of analog integrated circuits is a development of new and modernization of existing designs of integrated elements without significantly changing of a technological route of integrated circuit manufacturing with a simultaneous creation of new integrated elements models. The article considers the results of experimental studies of the double gate junction field-effect transistor manufactured according to the 3CBiT technological route of JSC Integral. Based on the obtained results, the electrical model of double gate junction field-effect transistor is proposed, which describes the features of its application in analog integrated circuits. Comparison of I-V characteristics of measurements results and created model simulation are presented. A small capacity and a reverse current of a double gate junction field-effect transistor top gate, an ability to compensate for the DC (direct current) component of an input current provide a significant improvement in the characteristics of analog integrated circuits such as electrometric operational amplifiers and charge-sensitive amplifiers. The developed double gate junction field-effect transistor can be used in signal readout devices required in the analog interfaces of space instrument sensors and nuclear electronics.

A multi-differential operational amplifier, called OAmp3, designed for operation at temperatures up to minus 197 °С and developed on bipolar transistors and junction field-effect transistors of the master slice array МН2ХА030, is considered in the article. The circuitry features of the OAmp3 allow, due to the use of various negative feedback circuits, to implement a set of functions necessary for signal processing on a single amplifier: amplification (or current – voltage conversion), filtering, shift of the constant output voltage level. The performed measurements of OAmp3, connected as instrumentation amplifier circuit, showed that all manufactured products retain their performance in the temperature range from minus 150 °С to 20 °С, and individual samples – at minus 197 °С. It was found that the main reason for the loss of OAmp3 performance is an increase of the resistance of semiconductor resistors by almost 5.4 times at minus 197 °С compared to normal conditions and decrease in the junction field-effect transistor drain current. Together, these factors lead to decrease in the current consumption of the OAmp3 by almost 31 times at minus 180 °С compared to normal conditions. To reduce the temperature dependence of the current consumption and, thus, save the OAmp3 operability at low temperatures without changing the technological route of integrated circuits manufacturing, it is proposed to replace high-resistance semiconductor resistors with “pinch-resistors” formed on a small-signal p-junction field-effect transistor. The article presents the OAmp3 connection circuit in the form of an instrumental amplifier, the method and results of low-temperature measurements of experimental samples.

Structured arrays and master slice arrays are often used to reduce cost, design and test time for radiation hardened analog integrated circuits. One of such master slice arrays is МН2ХА030, which uses bipolar and junction field-effect transistors. The purpose of this article is to estimate the effect of ionizing radiation on the parameters of the operational amplifier OAmp2 and comparators ADComp1 and ADComp3 created on the МН2ХА030 master slice array. Еhe results of measurements of analog components after exposure to 60Co gamma quanta with an absorbed dose of up to 700 krad and a fast electron fluence of up to 2.9·1015 el./cm2 with an energy of 6 MeV are presented. The OAmp2 operational amplifier provides a satisfactory level of basic static parameters (input current, offset voltage, voltage gain) at a fast electron fluence of up to 3.7·1014 el./cm2 with an energy of 6 MeV. There are a decrease in the voltage gain and an increase in the offset voltage at electron fluence of greater than 1015 el./cm2. The latter can be caused by a decrease in the efficiency of the common-mode signal feedback integrated into operational amplifier with a significant drop in current gain of bipolar transistors. All considered analog components provide a satisfactory level of basic static parameters at a fast electron fluence of up to 3.7·1014 el./cm2 with an energy of 6 MeV and an absorbed dose of 60Co gamma quanta of at least 700 krad. It is assumed that resistance of OAmp2, ADComp1, ADComp3 to the action of 60Co gamma quanta is significantly higher and requires further research. The developed analog components can be used in signal reading devices required in front-end of sensors for space instrumentation and nuclear electronics.

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.

We have developed technology and construction solutions system to increase differential pairs (DP) of JFet with p- and n-channels identity, which are included into silicon complementary bipolar process of SPE “Pulsar” (Moscow). The possibility of creating several types of JFet DPs within the process is shown. The paper presents the results of experimental studies of two types of DP JFet designs with p- and n-channels for the spread of gate-source voltage ΔVGS depending on the drain current and drain-source voltage. The main features of the first design of p-channel JFets were the following: formation of drain/source area due to passive base of npn-transistor and deep collector areas for pnp-transistor; channel formation based on p-layer collector of pnp-transistor; formation of bottom gate using p+ buried layer; top gate formation due to active base and polysilicon emitter of npn-transistor. A feature of the second JFet design was top gate formation due to passive base. The designs of the first and second types of n-channel Jfet were formed similarly, taking into account the replacement of the applied areas of bipolar transistors with opposite ones in the type of conductivity. It was found that with increasing drain current ΔVGS decreases, and with increasing drain-source voltage ΔVGS at high currents increases for DP based on p-channel JFet with the first type of design. The maximum difference ΔVGS was in the range of 5–80 mV for a given differential pair JFet with a p-channel. On plots for DP p-channel JFet with the second type design a significantly lower voltage spread ΔVGS was shown: for example, for the drain current ID = 50 μA the voltage spread ΔVGS did not exceed 10 mV. In this case the voltage spread ΔVGS practially did not depend on drain-source voltage in contrast to differenctial pair of the first type. The second type JFet n-channel differential pairs like for the DP p-channel JFet provided lower spread values in comparison with the first type design: ΔVGS reached values of 5-20 mV. Moreover, for the design of the second type, a significantly weaker effect of the drain-source voltage on ΔVGS was observed at high current densities. The developed designs of differential pairs based on p- and n-channel JFet are recommended for use in organizing the production of CBiCJFet analog circuits, including operations at low temperatures.

An interview of Professor A. A. Maslenikov by Dr. S. N. Prokopenko.

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.

The article considers the effect of 60Co gamma rays on the characteristics (the major ones for the analog ICs) of SiGe n-p-n transistors of SGB25V technology: the voltage across the forward-biased base-emitter junction, the dependence of the static base current gain in the common-emitter (CE) configuration on emitter current, the output characteristic in the CE configuration.

The author reviews The Bosporan Anthropomorphic Sculptures: Cross-cultural and Interethnic Communications Through Time and Space (Nizhni Novgorod, 2012), by N. V. Moleva, Associate Professor of the Lobachevsky State University of Nizhni Novgorod. The research is based on a study of over three hundred anthropomorphic monuments on the territory of Bosporus, an ancient state that was founded along the Kerch Strait on the northern Black Sea coast.

Schematic and design of electronics module for avalanche photodiode signal′s readout based on the pair of specialized analog ICs, are considered. Main specifications including input noise charge vs signal source capacity are presented.

The article proposes a method of bandwidth extension of the analog integrated circuit of the variable-gain amplifier (VGA) based on SiGe BiCMOS technology with the rules of 0.18 µm. The designed VGA has a linear (in dB) control characteristic. The authors consider the VGA architecture and present its design outputs. They describe the properties of two modifications of the VGA integrated circuit – with classical correction of the response and with the circuit of the parasitic capacitance cancellation in the high-impedance node. The article shows that the second circuit solution allows increasing the upper frequency limit of the VGA by a factor of 1.8-2.

AIM: To study the spread of a number of indicators of subclinical atherosclerosis in patients with coronary heart disease (CHD) and the pattern of their relationship to their functional state and muscle mass/MATERIAL AND METHODS: Twenty patients with chronic forms of CHD were examined. Vascular wall stiffness was judged from pulse wave velocity (PWV) along elastic-type vessels, by calculating the carotid-femoral index (CFI). Endothelial function was estimated by endothelium-dependent vasodilation (EDV) in a reactive hyperemia test. Ultrasound scanning of the common carotid artery was used to estimate intima-media thickness. All the patients underwent bicycle ergometry; their exercise tolerance (ET) was determined by the amount of consumed oxygen when the metabolic equivalent (MET) was calculated; the percentages of active cell mass (ACM%) and lean mass (LM%) of total body weight were determined; the levels of total cholesterol, high- and low-density lipoprotein cholesterol, and triglycerides were estimated. A control group comprised 20 matched persons without CHD/RESULTS: A prognostically unfavorable increase of >12 m/sec in CFI was revealed in 20% of the patients with CHD and in 10% of the controls; endothelial vasomotor dysfunction (EDV

Aim. To study the prevalence of selected parameters of subclinical atherosclerosis and their association with muscle function and muscle volume in patients with different levels of cardiovascular risk (CVR). Material and methods. The study included 20 patients (11 men and 9 women; mean age 54,5±8,5 years) with chronic coronary heart disease (CCHD; mean duration 6,4±2,3 years) in the main group (MG), as well as 20 CCHD-free people in the control group (CG). Arterial stiffness was assessed by pulse wave velocity (PWV) and calculated carotid-femoral index (CFI). Endothelial function was assessed by endothelium-dependent vasodilatation (EDVD) in the reactive hyperemia (RH) test. Common carotid artery (CCA) ultrasound was performed in order to assess intima-media thickness (IMT) of carotid arteries. All participants underwent veloergometry (VEM); exercise capacity (EC) was measured by calculated metabolic equivalents (MET). Muscle tissue volume was assessed using a bioelectrical impedance analyser. The percentage of active muscle mass (%AMM) and fat-free muscle mass (%FFM), out of the total body mass, was calculated. Results. Increased CFI values >12 m/s, as a marker of adverse prognosis, were observed in 20% CCHD patients and in 10% of controls (z=0,17; p=0,87). Vasomotor endothelial dysfunction (EDVD 0,9 mm were observed in 55% and 15%, respectively (z=2,3; p=0,02). Most patients with pathologically increased arterial stiffness and vasomotor endothelial dysfunction had low EC. In CCHD patients with low EC, CFI significantly correlated with %AMM and %FFM (r=-0,32; p

The current-voltage curves (CVC) of n-p-n SiGe heterojunction bipolar transistors (HBT) are considered within the temperature range from minus -195˚С up to 25˚С, produced on the SGB25V technology of IHP. The experimental setup, the measurement technique and the connection features of transistors for elimination of the self-excitation are described. The special attention is paid to the temperature dependences of the static base current gain βF in the common-emitter configuration (CEC) and to the output CVC characteristics of transistor in the CEC.