The Instrumentation and Differential Difference Amplifiers of Sensor Systems Based on the New Microcircuit of the Structured Array MH2XA010

Dvornikov, O.V.; Prokopenko, N.N.; Bugakova, A.V.; Ignashin, A.A.

Home Authors Papers Year of conference Themes Organizations To MES conference

The Instrumentation and Differential Difference Amplifiers of Sensor Systems Based on the New Microcircuit of the Structured Array MH2XA010

Authors

Date of publication

2016

Abstract

The differential difference amplifiers (DDA) belong to one of the preferred directions of instrumentation amplifiers circuitry development for sensor systems [1-7]. They allow implementing unique interfaces on the base of classical operational amplifiers (OA), the creation of which is impossible, or it is connected with big power and component consumption. Nowadays, more than 30 modifications of DDAs are produced in lots all over the world. They are applied in various analog processors and are used effectively for electrical signals conversion of sensors of different physical nature.
One of the economically attractive methods of limited production of the integrated circuits (IC), including the radiation-hardened ones, is an application of the array chips (AC) and structured arrays (SA) [8]. The designers of sensor systems and communications-electronics equipment of various functional areas have more than 30 analog and analog-digital ACs and SAs, including 6 circuits, which are produced in Russia [8].
The new SA MH2XA010 (the main designer is OJSC “MRIMI” with the participation of Don State Technical University and “Research Institute for Nuclear Problems” of Belorussian State University) adds successfully the existing microelectronic products of this class, mainly by providing the radiation hardness of ICs. The SA has 6 functional cells with analog IP-modules, which are necessary for signal operating of the main sensor types, and also with active and passive elements. The microcircuit MH2XA010, produced by OJSC “Integral” (Minsk, the Republic of Belarus) since 2016, allows creating the most widely used precision interfaces of the sensor systems. The designing of ICs, based on SAs, is carried out at the level of IO-blocks.
The aim of this article is to consider the advanced and new variants of connection of the differential difference and instrumentation amplifiers to sensor systems based on the active components of microcircuit MH2XA010.
It is recommended to apply the chip MH2XA010 for creation of multichannel radiation-hardened integrated circuits, oriented on the work with the main modifications of bridge, optical, piezoelectric and other sensors. The advanced and also unconventional variants of construction of IAs, based on SA, – the multichannel adder-multiplexer of analog signals, IA with estimation of the measurand derivative, wideband IA with channel low-pass filters and others are given.
In practice the number of input ports of DDA can be changed by the designer from one to eight.
Each of OTAs of SA (the functional cell FC2, 16 pieces) also includes a power supply IPTAT, which has a logical input SelA for connection or disconnection of the corresponding input port of DDA (putting the circuit of OÒÀ on the current saving mode).
It is possible to construct practically all modifications of DDA on the base of SA MH2XA010 [1-7], including DDAs with paraphase output with up to eight input differential ports. Besides, the unused ports of DDA can be disconnected by logical signals SelA1-A8. It extends significantly the possibilities of designing of the definite analog interfaces. It also makes possible to use the principle of reconfigurable DDAs in the analog processors more effectively [9, 10].
The architecture of the multichannel adder-multiplexer of the potential signals without resistors of the feedback are suggested. The algebraic addition of a big number of steady signals on the base of classical OAs requires the use of a large number of precision resistors [11]. It is possible to use DDA based on SA MH2XA010 with a big number of input ports to solve the tasks of some input voltages adding. Such connection of SA MH2XA010 also allows providing its operation in the mode of multiplexer of up to 15 input voltages, including seven differential signals. Besides, the connection and disconnection of the required channel is provided by the logical signals, fed into each logical input SelA of DDA.
The adder of the analog signals, suggested in the article, can operate in two main modes. The first mode is a mode of multiplexer, where the external digital loop controller forms digital signals SelA1-A8, and the subsequent in time connection of only one of N input differential stages of DDA is provided. Besides, at the moment of connection of the i-th input differential stage (DS) the output voltage of the adder is equal to its input differential voltage.
It’s important to note, that the output differential voltage, which is proportional to the input differential voltage, is formed in the circuit of the adder during the whole period of time, in the range of which the i-th input DS is switched on.
The second operation mode of the adder is a precision algebraic addition of the chosen input voltages. It is provided due to the connection of the chosen quantity of the input differential stages at the digital inputs SelA1-A8.
Thus, the adder-multiplexer, based on SA, considered in this article, is a multifunctional programmable analog processor, which provides:
 the algebraic addition of the input differential and non-differential signals, preset by the digital inputs SelA1-A8 of DDA;
 the multiplexing of only differential signals;
 the noninverting or inverting multiplexing of the input non-differential voltages;
 the multiplexing of the input differential and non-differential signals.
The well-known multiplexers and adders of the analog signals don’t have this feature.
We should note, that all mentioned above qualities are realized, only if each of input differential stages has a wide range of active operation [2]. It is provided by the corresponding choice of the resistor RE in the circuits of ÎÒÀs of AS MH2XA010.
The reconfigurable differential difference operational amplifiers allow realizing a wide range of transfer ratios without resistors of the negative feedback [9]. When commuting the input ports of DDA on SA MH2XA010 with the help of logic inputs SelAi, and also changing the resistance RE between the inputs of OTAs of SA at the stage designing, it is possible to realize practically any preset values of transfer ratios (both positive and negative) on the base of the chip MH2XA010 without resistors of common negative feedback.
Analogically, the inverting amplifiers can be realized due to the commutation of the inputs of DDA.
The bridge connection of sensors are most popular in measuring technique. The instrumentation amplifiers, realized due to the IP-module connections of the microcircuit MH2XA010, can be used to convert the signals of the measuring bridge diagonal.
The circuit of IA [12], designed by the authors of this article, provides (when it is realized on SA) not only high measurement accuracy of the physical magnitude x, but also the estimation of its derivative . This extends significantly the areas of application of this IA, including the adaptive systems of automatic control.
The architecture of the instrumentation amplifier with the low-pass filter (LPF) is considered. The circuit of IA [13], suggested by the authors of this article, allows connecting LPF to each of amplification channels and forming the preset frequency range of IA. Such construction of IA decreases an error from the offset voltage because of the resistive elements of LPF due to the high common-mode rejection ratio in the input stages of the output DDA. Besides, LPF are characterized by low sensitivity to the parameter instability of resistors and capacitors [13].
The architecture of the instrumentation amplifier with the extended frequency range is given. The entering of the inherent compensation circuits of parasitic time constants of DDA to the circuit of instrumentation amplifier on SA MH2XA010 [14] allows extending its bandwidth by a factor of 3÷5 times.
The presence of two antiphase outputs in DDA based on SA also extends significantly the possibilities of their use in the analog interfaces, including active RC-filters, range stops, etc [1, 15, 16]. The main connection circuits of DDA of this class are given. Thus, the article is a of the brief information about the new microcircuit of the structured array MH2XA010, oriented on various applications in the sensor systems, is presented.
The advanced and also unconventional variants of construction of IAs, based on SA MH2XA010, – the multifunctional adder-multiplexer of analog signals, IA with estimation of the measurand derivative, wideband IA with channel low-pass filters and others are given.
The tested and certified analog IP-modules are used in the structure of SA MH2XA010; it makes possible to estimate the hardness of the created communications electronics equipment at the initial stages of its designing.
The results of the successful radiation tests of the analog blocks, similar in microcircuitry to the components of SA MH2XA010, allow confirming, that the particular microcircuits, created due to the interconnection wirings of IP-modules of SA, solving the specific tasks of the analog signal converter, will be radiation-hardened under the influence of fluence of the electrons of 31014 el/cm2 with energy of 4 MeV and absorbed dose of 3 Mrad of gamma-rays 60Ñî.
The presence of a big number of the preliminary formed active components in SA MH2XA010 can become the base for designing the radiation-hardened differential difference operational amplifiers and instrumentation amplifiers on its base for the analog processors and converters of electric signals of sensors of various physical natures.

Keywords

instrumentation amplifier, differential difference operation amplifier, structured array, sensor interface, sensor systems, radiation hardness, analog integrated circuits.

Library reference

Dvornikov O.V., Prokopenko N.N., Bugakova A.V., Ignashin A.A. The Instrumentation and Differential Difference Amplifiers of Sensor Systems Based on the New Microcircuit of the Structured Array MH2XA010 // Problems of Perspective Micro- and Nanoelectronic Systems Development - 2016. Proceedings / edited by A. Stempkovsky, Moscow, IPPM RAS, 2016. Part 3. P. 106-113.

URL of paper

http://www.mes-conference.ru/data/year2016/pdf/D050.pdf