Reference Voltage Source Research Articles

Design of a bandgap reference voltage source with low temperature coefficient and high precision

This paper proposes a high-precision, low-temperature coefficient, and repair-free bandgap reference power supply circuit. This kind of bandgap reference source adopts the way of double-loop feedback, namely through two amplifiers to clamp the voltage to improve the performance of the circuit. The band gap reference source is mainly composed of four parts, including: band gap reference core circuit, amplifier, start-up circuit and Gaussian current compensation circuit. This article mainly analyzes the working principle of the core circuit of the bandgap reference, and derives the mathematical formula of the circuit. When the power supply voltage is 1.8V, the circuit is simulated in the temperature range of -40°C to 125°C with the Hspice software, and the reference source outputs stably. The voltage is 1.25V±4mv, the temperature coefficient is 3.7ppm/°C, and PSRR at low frequencies is -68dB.

Design and simulation of reference voltage sources circuit in lasers

AbstractFor the design of reference voltage source circuits in lasers, there is a problem of low accuracy using general design approach, this paper proposes an improved high‐precision voltage source circuit design. Firstly, a suitable reference voltage source chip is selected, then the excitation source circuit with better stability is designed, a high‐order filter is designed for filtering, and finally a compensation circuit is designed to improve the accuracy of the lasers voltage source. The effect of the designed voltage source circuit was verified, and the simulation results showed that the designed voltage source circuit was improved in output voltage accuracy, stability, and noise level, achieving a voltage noise level of 0.978 μV/Hz1/2 at 0.1 mHz at an input voltage of 2V. The validity of the voltage source circuit used for the lasers is verified, providing a high reference value for improving the lasers accuracy in laser spectroscopy.

Degradation processes in tungsten filaments at high temperatures

Degradation processes in tungsten filaments of lighting lamps under normal operating conditions are experimentally studied. The duration of each measurement in continuous mode is about 18 hours. To increase the measurement accuracy, subtraction (compensation) of the constant component of the voltage is used. To compensate for the constant component of the voltage, a low noise reference DC voltage source is used. Using this scheme allowed decreasing the influence of the inherent noise of power supplies without suppressing degradation processes. It is shown that the relative change in resistance during the measurement does not exceed 2.8·10−3. It is also shown that the joint influence of voltage fluctuations of power supplies and low noise reference voltage source on the measurement results corresponds to a relative change in a resistance equal to 2.8·10−4. The study of degradation processes can be used to assess the reliability (and durability) of products in electrical engineering and radio electronics.

Design of a High-precision 5V/10V DC Voltage Reference Source

This paper introduces a self-developed DC voltage source, which uses the Zener reference LTZ1000 as the voltage reference element. Selecting high precise resistors and using appropriate measures to insulate and isolate, the short—time relative stability of 7V output voltage provided by LTZ1000 is 1.5×10-8. The voltage of 10V is increased up by a network, composed by high precise resistors with the same temperature coefficient, and its short—time relative stability is 2.2×10-8. The voltage of 5V is divided by a network, composed by high precise resistors with the same temperature coefficient, and its short—time relative stability is 3.6×10-7. The circuit is suitable for signal acquisition, voltage calibration and other applications.

A Low-Noise DC Voltage Stabilizer Based on a General-Purpose Reference Voltage Source

A Low-Noise DC Voltage Stabilizer Based on a General-Purpose Reference Voltage Source

Design of a fuzzy PID controller for a MEMS tunable capacitor for noise reduction in a voltage reference source

This study presents a conventional Ziegler-Nichols (ZN) Proportional Integral Derivative (PID) controller, having reviewed the mathematical modeling of the Micro Electro Mechanical Systems (MEMS) Tunable Capacitors (TCs), and also proposes a fuzzy PID controller which demonstrates a better tracking performance in the presence of measurement noise, in comparison with conventional ZN-based PID controllers. Referring to importance and impact of this research, the proposed controller takes advantage of fuzzy control properties such as robustness against noise. TCs are responsible for regulating the reference voltage when integrated into Alternating Current (AC) Voltage Reference Sources (VRS). Capacitance regulation for tunable capacitors in VRS is carried out by modulating the distance of a movable plate. A successful modulation depends on maintaining the stability around the pull-in point. This distance regulation can be achieved by the proposed controller which guarantees the tracking performance of the movable plate in moving towards the pull-in point, and remaining in this critical position. The simulation results of the tracking performance and capacitance tuning are very promising, subjected to measurement noise.Article HighlightsThis article deals with MEMS tunable capacitor dynamics and modeling, considering measurement noise.It designs and applies fuzzy PID control system for regulating MEMS voltage reference output.This paper contributes to robustness increase in pull-in performance of the tunable capacitor.

Design of a Fuzzy Adaptive Sliding Mode Control System for MEMS Tunable Capacitors in Voltage Reference Applications

Micro electro mechanical system (MEMS) tunable capacitors (TC) are major elements in ac voltage reference sources (VRS). Physical parametric uncertainties, external electrostatic disturbance, and measurement noise malfunction their operation and ruin the preciseness of the VRS output voltage. Our objective problem is the design of a controller to cope with the mentioned parametric uncertainties, noise, and disturbance. Our applied method is the design and employment of a proportional integral fuzzy adaptive sliding mode controller (FASMC). Both terms of matched and unmatched uncertainties as well as external disturbance and measurement noise are all addressed in this article to generate a stable VRS output for the first time. Not only does this article contribute to the employment of a FASMC to enhance robustness in the drive of the capacitor, but also it benefits the reduction of the chattering effect due to fuzzy regulation in the switching term of the control law. Moreover, the automatic fuzzy adjustment in the controller, which is used for estimation of the coefficients in the sliding surface error dynamical equation, facilitates the specification of those coefficients, which can be time consuming in simulation affairs. Clarifying the importance of the proposed fuzzy adaptive sliding mode controller, this article reviews some previous controllers for MEMS TC in comparison with the proposed fuzzy controller, demonstrating its enhancement in comparison with previous schemes.

An adaptive sliding mode controller design to cope with unmatched uncertainties and disturbance in a MEMS voltage reference source

Tunable micro-electro-mechanical systems (MEMS) capacitors as the fundamental parts are embedded in MEMS AC voltage reference sources (VRS). Being concerned with the accuracy of the output voltage in the reference sources, it gets important to address uncertainties in the physical parameters of the MEMS capacitor. The uncertainties have the great inevitable potentiality of bringing about output voltage perturbation. The output deterioration is more remarkable when the uncertainties are accompanied by disturbance and noise. Manufacturers have been making great attempts to make the MEMS adjustable capacitor with desired rigorous physical characteristics. They have also tried to mitigate physical parameter veracity. However, ambiguity in the values of the parameters inescapably occurs in fabrication procedures since the micro-machining process might itself suffer from uncertainties. Employing a proportional integral (PI) adaptive sliding mode controller (ASMC), both terms of matched and unmatched uncertainties as well as the disturbance, are addressed in this work for the MEMS AC VRS so that a strict voltage is stabilized while the system is simultaneously subjected into uncertainties and exogenous disturbance. Cross-talk, some inertial forces, and electrostatic coercions may appear as matched and unmatched disturbances. Alteration in stiffness and damping coefficients might also take place as matched uncertainties due to variations in the fabrication process or even working environment. The simulation results in the paper are persuasive and the controller design has shown a satisfactory tracking performance.

Design of a new voltage reference source

Current reference is a very important module in analog circuits. The main purpose of this design is to provide a stable reference voltage for a switch magnetism-sensing circuit. Because of the inherent characteristics of the circuit, the reference voltage is set to 3.3V. In this paper, the reference voltage source is designed to have a wide input range, a stable output and a good temperature characteristic. In this paper, the simulation results of the reference voltage and the complete design layout are described, and a current reference is achieved, which is independent of process, voltage and temperature, with little area increases only. The simulation results based on a 4 μm 25 V bipolar process verify the correctness of the theoretical analysis and the feasibility of the proposed methods.

АПАРАТНО-ПРОГРАМНА ВБУДОВАНА СИСТЕМА ЧАСТОТНОЇ СЕЛЕКЦІЇ СИГНАЛУ НА ОСНОВІ ГІРАТОРА

The work is devoted to the problem of frequency-selective signal conversion in microelectronic sensor devices. It has been shown that the signal path of such devices, in particular, sensor nodes in the concept of the Internet of Things, must meet the requirements of embedded systems using a mixed analog-digital front end. The analysis of the signal transformation of photovoltaic sensors, in particular the problem of a significant parasitic influence of extraneous non-informative optical radiation and electromagnetic interference, has been carried out. SPICE models of photovoltaic sensor signal circuits providing frequency selection on bandwidth filters have been synthesized. The main approaches of hardware-software implementation of the built-in system of frequency selection with the mixed-signal transformation are considered. The signal path of the embedded system includes a gyrator, a software-controlled amplifier, a synchronous demodulator, an analog-to-digital converter, and a digital filter. The implementation is carried out on the platform of the programmable system on a PSoC chip. The integrated circuits of the PSoC 5 LP Family Cypress Semiconductor Corporation are used with a wide range of programmable analog front-end nodes, in particular operating amplifiers, comparators, units on switching capacitors, reference voltage sources on the principle of the forbidden zone, analog multiplexers, signal synthesizers, etc. The efficiency of the mixed analog and digital signal conversion is shown.

A CMOS Bandgap Reference Circuit with a Temperature Coefficient Adjustment Block

A bandgap reference voltage source with a temperature coefficient adjustment block was proposed. The bandgap topology employs current summation and the circuit was designed through metaheuristic algorithms in a 0.35-mm CMOS technology. Simulations with typical parameters show that the designed circuit has temperature coefficient of 15 ppm/0C, line regulation of 263 ppm/V, and current consumption of 2.71 uA in 1.0 V power supply. An additional 3-bit temperature adjustment block allowed keeping the temperature coefficient values lower than 26.6 ppm/0C for 90% of the circuits, without interfering with the reference voltage output or line regulation values.

CMOS Schmitt – Inverter-Based Internal Reference Comparator Array for High Temperature Flash ADC

ABSTRACT Localized data conversions for sensors placed under harsh environmental conditions often require Analog to Digital Converters (ADC) capable of working under wide operating temperature range. Even though the fastest analog to digital converter, flash ADC is omitted from the high temperature regime due to the requirements of reference voltage source, reference voltage divider and a comparator array capable of providing stable operation under wide operating temperatures. A CMOS Schmitt inverter-based internal reference comparator array for flash ADC which is efficient in terms of area and power consumption, capable of working under wide temperature range is presented in this paper. The proposed idea replaces the reference voltage source, resistive reference voltage divider and differential comparator array of a conventional flash ADC by an array of suitably sized Schmitt inverters. The circuit was simulated for static and dynamic characteristics with gpdk 180 nm library using cadence virtuoso simulation suite. The voltage transfer characteristic curve (VTC) of the proposed comparator array was found invariable when a temperature sweep in the range of −40 to 170 degree Celsius was performed. Each of the comparator in the proposed array consumes a silicon area of 40.68 and the average dynamic power consumption per cycle is estimated as 103.1 uW.

The simulation of influence of main components’ parameters of reference voltage sources on output voltage

The aim of the research is to develop a model of the reference voltage source that can be modeled the influence of the main structural components’ parameters of reference voltage source on the accuracy and temperature stability of the output voltage. The article analyzes the current state of reference voltage sources in integrated circuits. It was established that reference voltage sources are one of the main blocks of each integrated chip. It was found that requirements are for these sources are the next: they must have low sensitivity to changes in supply voltage, temperature, and deviations of the parameters of the technology process. In this case, the reference voltage sources must operate at a supply voltage equal to or less than 1V to meet modern aspects of the application. A possible approach to the construction of a reference voltage source having a temperature-independent output voltage and capable of operating at a supply voltage equal to or less than 1V is proposed in this article. This solution has the ability to implement in the standard CMOS technology for integrated circuits. An analysis of possible sources of error that degrade the accuracy of the output voltage of the reference voltage source is provided. It was established that the bias voltage of the operational amplifiers has the strongest effect on the accuracy of the output voltage. An idealized model is proposed, which contains ideal resistors and operational amplifiers – the components that most strongly affect the accuracy and stability of the output voltage of the voltage references. An operational amplifier model has been developed that is able to model the input bias current, input bias voltage, input resistance, differential gain, output resistance and frequency response of the operational amplifier. The influence of voltage gain, bandwidth, output resistance of the operational amplifier, input bias voltage on the nominal output voltage and the temperature coefficient are investigated. A regression analysis was performed to display in a polynomial of the 4th order form like , temperature dependence of the currents generated in the circuit. This allows you to choose the correct values of current transfer coefficients in the current mirrors to reduce the temperature dependence of the output voltage.

A measurement method for lossy capacitive relative humidity sensors based on a direct sensor-to-microcontroller interface circuit

A new time-domain measurement method for determining the capacitance and resistance values of lossy relative humidity capacitive sensors is presented. The method is based on a direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators and timers. The interface circuit consists only of four reference resistors (two reference resistors if a microcontroller includes a voltage reference source), a given sensor and a microcontroller. A systematic error correction algorithm based on a correction dictionary and the M-multiple measurement approach are also proposed in the paper. Experimental investigations were carried out using a prototype device based on an 8-bit ATXmega32A4 microcontroller. The experimental research confirmed that the relative errors of measurement of capacitance introduced by the interface circuit are less than 0.71% (for capacitance values 100–286pF), and the relative errors of measurement of resistance are less than 0.74% (for resistance values 1–10MΩ).

Robust adaptive sliding mode control of a MEMS tunable capacitor based on dead-zone method

Uncertainty in parameters of a tunable Micro Electro Mechanical System (MEMS) capacitor, as the main component of AC Voltage Reference Source (VRS), is significant to obtain a precise output voltage unaffected by disturbance and noise. Although attempts are done to craft the capacitor with desired physical specification and improve accuracy of parameters, parametric uncertainties transpire in manufacturing due to micro-machining shortcomings. First off, this paper remarks design of a Robust Adaptive Sliding Mode Controller (RASMC) and its application for the MEMS AC VRS for the first time so that it can produce a stable precise regulated output at presence of uncertainties and disturbance. Secondly, it makes a comparison between the proposed novel controller and our previously designed ASMC. The comparison reassures one of robustness at exacerbating conditions in the tunable capacitor dynamics. The novelty is employment of the dead zone-based ASMC to manage parametric uncertainty and disturbance in the MEMS tunable capacitor. It also contributes to adaptive sliding mode control of the dynamics with stiffness and damping coefficients, which are non-slowly-varying time-dependent parameters, approaching dead-zone method. Uncertainty in the plate mass besides bounded time-variant uncertainty in stiffness and damping are considered. These restrictions were not deemed in the previous design.

Approximation Piecewise Stabilization of the Thermal Voltage Coefficient of Reference Voltage Sources

There are many cases in which standard reference voltage sources exhibit a number of flaws, in particular, unipolarity and a high thermal voltage coefficient. The latter flaw is especially important, as reference voltage sources are used, as a rule, in a broad range of temperatures. This article considers the technique of approximation piecewise stabilization of the thermal voltage coefficient and the circuit design for constructing a bipolar source of reference voltage with a low temperature coefficient, a source that is configured on the basis of standard integrated circuits of operational amplifiers. In terms of thermal voltage coefficient, the proposed circuit design is among the best examples of commercial reference voltage sources usable in a broad range of feeding voltages and characterized by bipolar output voltages.

Two-Stage Reduction in the Output Noise Level of Voltage Sources

The development of digital technologies that are widely used in industry and agriculture places high demands on voltage reference sources for a number of parameters, each of which is important in its own way. However, a further increase in the resolution of analog-to-digital and digital-to-analog converters and, therefore, of all digital signal processing is impossible without an improvement in such a quality indicator of reference voltage sources as the noise level. In this paper, we discuss the method and schematic solution of designing a low-noise source of stable dc voltage base on standard integrated circuits of voltage stabilizers. The schematic solution provides an ability to reduce the output noise level of the corresponding reference voltage sources to a level slightly higher than the intrinsic noise level of operational amplifiers used as a part of the device block circuits, maintaining the polarity and stability of the device output voltage relative to the output voltage of the used integrated circuit of a voltage stabilizer, and reduction in capacitance of used capacitors compared with known circuit solutions.

Methods of Compensation for the Temperature Dependence of the Reference Voltage Sources of Integrated Circuits

The basic principles of reference voltage source construction are considered in the article. Possible sources of error of the output reference voltage, advantages and disadvantages of the existing architectural solutions of the reference voltage sources are analyzed. An architectural solution for the construction of a reference voltage source with higher order nonlinearities compensation is proposed, which has a temperature independent output voltage and is capable of operating at a supply voltage equal to or below 1 V. This solution has the possibility of implementing in the standard CMOS technology. Recommendations for compensation for the error caused by the offset voltage of the operational amplifier are given.In the modern world, integrated circuits (ICs) are the nucleus of virtually all electronic systems. When designing many ICs, one of the most important tasks is to generate accurate voltages for the entire circuit. The ICs that create these voltages are often referred to as the reference voltage sources. The reference voltage is a major component of both fully analog and digital circuits and even memory elements. There is a particular demand for low voltage power supplies as it is required for modern gadgets, mobile phones, laptops, cameras, etc. They should have low sensitivity to changes in power supply, possible deviations in the parameters of the manufacturing process and temperature.The reference voltage sources in standard CMOS technology have high precision output voltage, but temperature dependence is a problem. Another problem of such circuits is the inability to operate with a supply voltage below 1 V. The reasons for this are two: the principle of their operation is based on a bandgap of silicon equal to 1.25 V, which already exceeds 1 V of power; the second reason is that low voltage sources of reference voltage contain an operational amplifier, which should also operate at low power. In this case, low voltage power supply generators have poorer accuracy rates than classical implementation. Therefore, improving the characteristics of reference voltage sources while being able to operate at a supply voltage close to or below 1 V is a problem and requires a compromise solution.In the article was analyzed generators that provides proportional to absolute temperature (PTAT) voltage at their outputs, generators that provides complementary to absolute temperature (CTAT) voltage at their outputs. The source of the high-order nonlinearity was analyzed.The schematic of implementing reference voltage generators was proposed. The formulas for output voltage was derivated. The basic principles of operation of proposed schematic was described. The voltage reference, which utilizes the temperature-dependent currents generated from the parasitic n-p-n and p-n-p bipolar junction transistor devices in the CMOS process, is presented.

Channel of Measurement and Indication of 220 Voltage in the Device «Quality-E1»

At the V.M. Glushkov Institute of Cybernetics the “Yakist-E1” – electric power quality measuring device, was developed. The device uses new method and structure of a quality determination, and is based on calculating the deviations from the nominal values of voltage and frequency values. The methodical error of level quantization for a 10-bit ADC is ± 0.1%. To achieve an approximation error of ± 0.1%, it is necessary to measure the voltage near the amplitude value after 170 μs. The channel for voltage measuring in the device consists of a voltage transformer, a high-precision resistive divider that scales and biases the input voltage, a reference voltage source (VREF) and an ADC, which built into the microcontroller. The device “Yakist-E1” uses an 8-bit microcontroller type C8051F320, which has a 10-bit ADC with an input signal range from 0 to 2.5 V. The output voltage of the VREF from the chip to the controller chip can vary from 2.38 V to 2.5 V. In addition, different transformer sensors may have different transfer characteristics, which may be non-linear. Therefore, to indicate the values of the measured voltage on the alphanumeric indicator, a piecewise linear approximation of the results of measuring the ADC is used. The transfer and temperature characteristics of the voltage transformer were measured for forward and reverse passages, and, according to the results, was discovered that the temperature error is very small and practically does not affect the accuracy of the sensor and the sensor has hysteresis, the calculated errors do not exceed ± 1%. All this errors were corrected. To determine the deviation of the amplitude value from the nominal value, only 8 low-order bits of the ADC are used. This trick grants that ADC result can be processed by a single command of the microcontroller, which increases processing speed of the channel.

Design of an adaptive sliding mode controller with a sliding mode Luenberger observer for the MEMS capacitive plates

Uncertain parameters in a MEMS tunable capacitor, as one of the fundamental elements in a MEMS AC voltage reference source (VRS) structure, is an important issue for acquisition of a rigorous voltage in the VRS output. The output is mostly supposed to be destroyed by harmful disturbance and noise. Even though the manufacturers make attempts to build MEMS tunable capacitor with desired characteristics in thorough compliance with the initial major design, uncertainties in the parameters inescapably do exist in manufacturing process on the ground of deficiencies in various procedures. This paper mainly remarks an adaptive sliding mode controlling design with a sliding mode Luenberger observer and its application for a MEMS tunable capacitor. The control design is done considering matched and unmatched terms of uncertainties and disturbance. The advantageous outcome is that the VRS could be generating a stable precise regulated output voltage owing to correct distance adjustment of the capacitor charged plates. The design exploits the sliding mode observer to get rid of extra usage of plate position measurement in the control structure. The controller alleviates the system output of the matched and unmatched disturbance which could exist dynamically because of cross stiffness and damping in addition to other inertial and electrostatic disturbing forces. The matched uncertainties, such as stiffness and damping change, might appear due to variation in fabrication procedures or working condition. The simulation yields are satisfactory and depict a persuasive tracking performance as well as regulation about the pull-in point.