Low-voltage Operation Capability Research Articles

A novel instrumentation amplifier with high tunable gain and CMRR forbiomedical applications

A new design of current mode instrumentation amplifier (CMIA) with tunable gain and low voltage operation capability is proposed in this paper, which is suitable for biomedical signals processing, especially in electrocardiogram (ECG). It consists of a new design of current differencing transconductance amplifier (CDTA) and dual z copy CDTA (DZC-CDTA). The gain of the proposed CMIA is controlled by a MOS-based tunable resistor. The main advantage of the proposed CMIA is its high gain that can be tuned over a significant range with the help of two resistances. The performance of the proposed instrumentation amplifier is evaluated through simulation results on Cadence Virtuoso using SCL 180 nm CMOS technology. From simulation results gain, common mode rejection ratio (CMRR), power supply rejection ratio (PSRR), %THD and -3 dB bandwidth of proposed instrumentation amplifier are obtained as 55.09?81.12 dB, 90.42-116.5 dB, 97.3 dB (+PSRR), 114.2 dB (- PSRR), 1.5% and 9.5-165 kHz, respectively. The performance of the proposed design is also examined against PVT variations. The performance of proposed CMIA is compared with other existing designs available in the literature, which clearly shows the competency of the design. The post layout simulation results confirm the on-chip implementation feasibility.

PMSM low voltage ride through based on Coordinated Control Strategy

Based on the analysis of the operation characteristics of the fault of direct-drive permanent magnet wind turbine and the existing protection strategies, in order to improve the low-voltage operation capability of direct-drive permanent magnet wind turbine, a new coordinated control strategy for low-voltage crossing is proposed in this paper, which includes DC brake system control of unloading circuit, double second-order generalized integral phase-locked control, extracting positive and negative sequence of grid voltage and reactive power control on grid side. Based on the common three-phase symmetrical drop fault and asymmetrical fault caused by single grounding short circuit in power grid, PASCAD simulation experiment is conducted to verify the low voltage traversing ability of wind turbine.

A Hybrid-Arm Modular Multilevel Converters Topology With DC Low Voltage Operation and Fault Ride-Through Capability for Unidirectional HVDC Bulk Power Transmission

In this paper, a novel hybrid-arm modular multilevel converters (HA-MMCs) topology with DC low voltage operation and fault ride-through capability is proposed for unidirectional HVDC bulk power transmission. The HA-MMCs topology is a combination of two types of converter arms: the half-bridge sub-module based arm (HBSM-arm) and the diagonal bridge sub-module based arm (DBSM-arm). Replacing the traditional HBSM-MMC, the HA-MMCs are operated in current and reactive power control modes during normal conditions and can work as the rectifier or the inverter. Since the DBSM can provide bipolar voltages with unipolar currents, the HA-MMCs need not change its control strategy under DC low voltage conditions caused by the high-impedance faults. Under DC pole-to-pole or pole-to-ground faults, the HA-MMCs can both clear the DC fault current and work as the static synchronous compensator (STATCOM) to provide reactive power to support the AC grid. Compared with other MMC topologies with DC fault ride-through capability, the HA-MMCs topology is more economical for significantly decreasing the number of power devices. The operation states, control strategy and DC low voltage operation capability of the HA-MMCs are presented and simulation results of the LCC-HA-MMC hybrid system using PSCAD/EMTDC validate the characteristics and advantages of the HA-MMCs.

0.5 V sixth-order Chebyshev band-pass filter based on multiple-input bulk-driven OTA

This paper presents a low-voltage sixth-order Chebyshev band-pass filter based on multiple-input operational transconductance amplifier (MI-OTA). The used voltage supply is 0.5 V and the filter employs six MI-OTAs and six capacitors. The third intermodulation distortion (3rd IMD) is below 1% for input sine wave signal with peak-to-peak up to rail-to-rail while the dynamic range (DR) is 66.8 dB. In order to insure low-voltage operation capability, extended linear range, increased voltage gain of the MI-OTA, the multiple-input bulk-driven transistor (MIBD) along with self-cascode techniques have been used. As a result, the proposed MI-OTA based on MIBD is capable to work with 0.5 V supply voltage and consumes power in the range of (2.5–1.2E3) nW for tunable bias current in the range from 1 nA to 500 nA. The MI-OTA and the filter circuits were designed and simulated in Cadence/Spectre environment using 0.18 µm CMOS process from TSMC. The simulation results agree well with theory and confirm the filter functionality.

A Recent Progress of Spintronics Devices for Integrated Circuit Applications

Nonvolatile (NV) memory is a key element for future high-performance and low-power microelectronics. Among the proposed NV memories, spintronics-based ones are particularly attractive for applications, owing to their low-voltage and high-speed operation capability in addition to their high-endurance feature. There are three types of spintronics devices with different writing schemes: spin-transfer torque (STT), spin-orbit torque (SOT), and electric field (E-field) effect on magnetic anisotropy. The NV memories using STT have been studied and developed most actively and are about to enter into the market by major semiconductor foundry companies. On the other hand, a development of the NV memories using other writing schemes are now underway. In this review article, first, the recent advancement of the spintronics device using STT and the NV memories using them are reviewed. Next, spintronics devices using the other two writing schemes (SOT and E-field) are briefly reviewed, including issues to be addressed for the NV memories application.

A low-voltage low-power 0.25 µm integrated single transistor active inductor-based filter

In this paper we present a 0.25 µm BiCMOS Technology bandpass filter implementation based on a single transistor Active Inductor (AI). The high-Q AI integrated circuit is designed by the use of a single transistor with a compensation network that allows to control both the inductance and its series resistance value. The AI-based high frequency bandpass filter has a center frequency of 2000 MHz (useful for radio and radar applications) and a 3 dB bandwidth of about 6 MHz with a quality factor of about 330. Moreover, a discrete prototype of the same AI has been also designed and measured. Measurements results on the discrete board have shown a 3 dB bandwidth of about 10 MHz, a noise figure of 6 dB, a ?10 dBm P1 dB compression point with 80 dB dynamic range. The power supply is 1.2 V with a power consumption of 800 µW showing low-voltage low-power operation capability together with good general performances.

COMPOSITE TRANSISTOR CELL USING DYNAMIC BODY BIAS FOR HIGH GAIN AND LOW-VOLTAGE APPLICATIONS

In this work, a new composite transistor cell using dynamic body bias technique is proposed. This cell is based on self cascode topology. The key attractive feature of the proposed cell is that body effect is utilized to realize asymmetric threshold voltage self cascode structure. The proposed cell has nearly four times higher output impedance than its conventional version. Dynamic body bias technique increases the intrinsic gain of the proposed cell by 11.17 dB. Analytical formulation for output impedance and intrinsic gain parameters of the proposed cell has been derived using small signal analysis. The proposed cell can operate at low power supply voltage of 1 V and consumes merely 43.1 nW. PSpice simulation results using 180 nm CMOS technology from Taiwan Semiconductor Manufacturing Company (TSMC) are included to prove the unique results. The proposed cell could constitute an efficient analog Very Large Scale Integration (VLSI) cell library in the design of high gain analog integrated circuits and is particularly interesting for biomedical and instrumentation applications requiring low-voltage low-power operation capability where the processing signal frequency is very low.

Differential voltage current controlled current conveyor with low-voltage operation capability

A novel differential voltage current controlled current conveyor topology is introduced in this article. It has the capability for operating in a low-voltage power supply environment and, also, offers resistorless filter realisations. The main attractive offered benefit is that the handling of AC signals is exclusively performed by nMOS transistors and, thus, the proposed element has capability for high-frequency operation. The performance of the proposed cell has been experimentally verified through the realisation of two 3rd-order filters, derived according to the leapfrog and component substitution methods. The filter topologies have been fabricated through the AMS 0.35 µm CMOS process.

Low-Voltage Complex Filters Using Current Feedback Operational Amplifiers

A novel complex filter topology realized using current feedback operational amplifiers as active elements is introduced in this paper. Offered benefits are the low-voltage operation capability and the requirement for employing only grounded passive elements. Two application examples are provided, where the frequency behavior of the derived filters fulfills the ZigBee and Bluetooth standards, respectively. Their performance evaluation has been done through simulation results at postlayout level, using MOS transistor models provided by AMS C35B4 CMOS process.

A Subthreshold-MOSFETs-Based Scattered Relative Temperature Sensor Front-End With a Non-Calibrated $\pm 2.5^{\circ}{\rm C}$$3\sigma$ Relative Inaccuracy From -$40^{\circ}{\rm C}$ to 100$^{\circ}{\rm C}$

This paper presents a subthreshold MOSFETs-based scattered relative temperature sensor front-end operating at a low supply voltage. Dynamic element matching and dynamic offset cancellation have been implemented to minimize the errors induced by device mismatches. An individual proportional-to-absolute-temperature (PTAT) voltage generator was first implemented to verify the low voltage operation capability and the mismatch-error correction. A low voltage reference circuit has been also designed and tested. A gate-bulk-driven error correction amplifier is proposed in order to minimize the offset error and maintain low voltage operation. The scattered relative temperature sensor front-end was then implemented in AMI 0.5 μm CMOS process with an array of 5 × 5 sensor nodes across the chip. The minimum supply voltage was measured as 1 V over -40-100°C with a typical N-JP-type threshold voltage of around 0.8 V and 0.9 V at room temperature, respectively. The measured relative inaccuracy was less than ±2.5°C without calibration. To the best of the authors' knowledge, this is the first time that non-calibrated on-chip relative temperature monitoring accuracy is reported. Furthermore, the multi-location thermal monitoring function has been experimentally demonstrated and a 2°C/mm on-chip temperature gradient was detected.

Sinh-Domain linear transformation filters

A new systematic method for designing Sinh-Domain linear transformation (LT) filters is introduced in this article. For this purpose, a substitution scheme containing the Sinh-Domain LT equivalent of each passive prototype has been introduced. The proposed equivalents have been realised by employing appropriate Sinh-Domain building blocks with low-voltage operation capability. As an example, a third-order Sinh-Domain elliptic LT filter has been designed and its performance has been evaluated through simulation results. In addition, a detailed comparison with the corresponding Sinh-Domain and log-domain counterparts has been performed and the obtained results have been further discussed.

High-Precision Differential-Input Buffered and External Transconductance Amplifier for Low-Voltage Low-Power Applications

Recently, the demand for low-voltage low-power integrated circuits design has grown dramatically. For battery-operated devices both the supply voltage and the power consumption have to be lowered in order to prolong the battery life. This paper presents an attractive approach to designing a low-voltage low-power high-precision differential-input buffered and external transconductance amplifier, DBeTA, based on the bulk-driven technique. The proposed DBeTA possesses rail-to-rail voltage swing capability at a low supply voltage of ±400 mV and consumes merely 62 μW. The proposed circuit is a universal active element that offers more freedom during the design of current-, voltage-, or mixed-mode applications. The proposed circuit is particularly interesting for biomedical applications requiring low-voltage low-power operation capability where the processing signal frequency is limited to a few kilohertz. An oscillator circuit employing a minimum number of active and passive components has been described in this paper as one of many possible applications. The circuit contains only a single active element DBeTA, two capacitors, and one resistor, which is very attractive for integrated circuit implementation. PSpice simulation results using the 0.18 μm CMOS technology from TSMC are included to prove the unique results.

A COMPACT CMOS POWER-ON-RESET PULSE GENERATOR DESIGN WITH LOW-POWER AND WIDE OPERATION RANGE

A compact power-on-reset pulse generator (POR-PG) circuit with a low-power and low-voltage operation capability is presented. Proposed POR-PG was fabricated in 0.5 μm 2P3M CMOS process. It was determined from simulations and measurements that proposed POR-PG works supply voltage levels between 1.8 V and 3.3 V and supply voltage rise times between 100 ns and 1 ms. POR-PG has very small silicon footprint. Layout size of proposed POR-PG circuit was 120 μm × 5 μm in 0.5 μm CMOS process. Comparing with other POR-PG circuits in the literature, proposed design enjoys lowest power consumption (< 6 μW), smallest silicon footprint, widest supply voltage range, and additional features such as brown-out detection capability. These achieved by using a unique cascadable POR delay element that consumes very low-power.

Low-voltage current controlled current conveyor

A novel second-generation Current Controlled Current Conveyor (CCCII) topology is introduced in this paper. Compared with the corresponding already introduced topologies, the proposed CCCII offers the advantage of low-voltage operation capability. In addition, due to the absence of PNP or PMOS transistors for handling ac signals, its performance in terms of maximum frequency of operation is improved.

Very low-voltage operation capability of complementary metal-oxide-semiconductor ring oscillators and logic gates

Operation of complementary metal-oxide-semiconductor (CMOS) logic gates at low supply voltages down to 100mV and ring oscillators down to 67mV is experimentally investigated. The measured voltage transfer characteristics of CMOS inverters and logic gates are explained using the subthreshold operation of MOS transistors. Robust control of ring oscillators allows for a tuning range of six decades in frequency with excellent sensitivity as low as 75mV per frequency decade at low voltages in the range from 0.2 to 0.5V, when body biasing of the metal-oxide-semiconductor field-effect transistors (MOSFETs) is also used. For the present state-of-the-art CMOS, the simple digital CMOS cells can operate properly at supply voltages down to 0.2V, but to achieve operation at lower voltages, additional circuitry is needed to maintain the matching between p- and n-MOSFETs, and the circuit complexity increases. Nevertheless, the experiments with ring oscillators demonstrated good performance of CMOS circuits down to the physical limit of two to three times the thermal voltage, while logic gates with stacked transistors need a supply of approximately four to six times the thermal voltage.

A 300-MHz-Band, Sub-1 V and Sub-1 mW CMOS SAW Oscillator Suitable for Use in RF Transmitters

An ultra low power CMOS SAW oscillator in the 300MHz-band that operates on a sub-1 V supply voltage and at sub-1 mW power consumption has been developed. The SAW oscillator is fabricated in a 0.35-μm fully depleted SOI (FD-SOI) process with low voltage operation capability. The SAW oscillator is configured as a type of Colpitts oscillator but consists of 3 cascaded amplifiers instead of a single amplifier. Although the circuit configuration is quite similar to the conventional Colpitts oscillator, this proposed configuration generates an excessively high negative resistance that even exceeds the theoretical limit of the conventional one.

A High Performance Square-Root Domain Integrator

In this work a true square-root domain integrator configuration is proposed, which is implemented using new current geometric-mean and multiplier/divider blocks. The main advantage of the proposed configuration, in comparison with previous realizations, is the immunity to the body effect. Additional important features are low-voltage operation capability, linear tuneability and design modularity.

Photonic switching by tunnelling-assisted absorption modulation in a GaAs sawtooth structure

We report on an electrically controlled optical modulator using a novel GaAs sawtooth structure. This structure consists of alternating n-type and p-type delta-doped GaAs. Modulation of tunnelling-assisted absorption is achieved by changing the internal electric field which in turn is controlled by external bias. Modulation of light intensity is demonstrated over a broad spectral range of Δλ > 100 nm. A contrast ratio of 1 : 1.7 of the opaque and transparent states is obtained. Low-voltage operation (ΔV < 5V) and potential high-speed capability make the new device an attractive candidate for future photonic switching systems.

A protecting layer for the dielectric in AC plasma panels

One of the important problems in the development of ac plasma panels is to produce panels that maintain stable characteristics for a long time. A new idea for using a protecting layer over the dielectric layer which isolates the electrodes from the gas was examined and good results were obtained. Moreover, besides stability, a considerable improvement of operating characteristics was achieved, including low-voltage operation capability. Sputtering of the protecting layer, which is thought to govern the life of plasma panels, occurs even to heat-resisting oxides of large binding energy, but the sputtering rate appears to be so slow that it hardly affects the panel life. Also, the rate of decomposition accompanying sputtering is small. The problem of cracks in the protecting layer, which is the cause of defective life characteristics in such respects as migration of the lead component of the dielectric layer onto the protecting layer and the direct exposure of the dielectric-layer glass to the discharge, was solved by process-technique improvements. This paper describes the merit of using a protecting layer, required performance for this layer, and experimental results, and discusses voltage stability and the results of selection of materials for it.