scholarly journals Class-C Linearized Amplifier for Portable Ultrasound Instruments

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 898 ◽  
Author(s):  
Hojong Choi
Keyword(s):  
Power Consumption ◽  
Output Voltage ◽  
Signal Amplitude ◽  
Piezoelectric Transducers ◽  
Battery Life ◽  
Potential Candidate ◽  
Portable Ultrasound ◽  
Dc Power ◽  
Class C ◽  
Main Components

Transistor linearizer networks are proposed to increase the transmitted output voltage amplitudes of class-C amplifiers, thus, increasing the sensitivity of the echo signals of piezoelectric transducers, which are the main components in portable ultrasound instruments. For such instruments, class-C amplifiers could be among the most efficient amplifier schemes because, compared with a linear amplifier such as a class-A amplifier, they could critically reduce direct current (DC) power consumption, thus, increasing the battery life of the instruments. However, the reduced output voltage amplitudes of class-C amplifiers could deteriorate the sensitivity of the echo signals, thereby affecting the instrument performance. Therefore, a class-C linearized amplifier was developed. To verify the capability of the class-C linearized amplifier, typical pulse-echo responses using the focused piezoelectric transducers were tested. The echo signal amplitude generated by the piezoelectric transducers when using the class-C linearized amplifier was improved (1.29 Vp-p) compared with that when using the class-C amplifier alone (0.56 Vp-p). Therefore, the class-C linearized amplifier could be a potential candidate to increase the sensitivity of echo signals while reducing the DC power consumption for portable ultrasound instruments.

scholarly journals Prelinearized Class-B Power Amplifier for Piezoelectric Transducers and Portable Ultrasound Systems

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 287 ◽  
Author(s):  
Hojong Choi
Keyword(s):  
Power Amplifier ◽  
Power Amplifiers ◽  
Heat Dissipation ◽  
Piezoelectric Transducers ◽  
Battery Life ◽  
Portable Ultrasound ◽  
Class A ◽  
Class B ◽  
Cooling Fans ◽  
Pulse Echo

Portable ultrasound systems typically suffer from unwanted heat and limited battery life, resulting in reduced system performance or the applicable number of piezoelectric transducer elements. This can be a bottleneck in widely used portable ultrasound systems. Class-A power amplifiers are typically used in portable ultrasound systems. However, unwanted heat dissipation needs to be reduced by using large cooling fans and heat pipe structures. To reduce unwanted heat, class-B power amplifiers may be a possible solution. However, the non-linearity of class-B power amplifiers could limit their integration with piezoelectric transducers because non-linearity in the high-voltage output of the power amplifiers deteriorates the sensitivity of portable ultrasound systems. To improve the linearity of the power amplifier, we developed prelinearized class-B power amplifiers for piezoelectric transducers and portable ultrasound systems. To verify our proposed method, we compared the performances of class-B and prelinearized class-B power amplifiers in their pulse-echo responses. Therefore, prelinearized class-B power amplifiers are a possible solution to produce better echo signal performance in piezoelectric transducers and portable ultrasound systems.

scholarly journals DC Power Consumption [Enigmas, etc.]

2021 ◽  
Vol 22 (7) ◽  
pp. 90-92
Author(s):  
Takashi Ohira
Keyword(s):  
Power Consumption ◽  
Dc Power

Low power aware pulse triggered flip flops using modified clock gating approaches

2018 ◽  
Vol 15 (6) ◽  
pp. 792-803
Author(s):  
Sudhakar Jyothula
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Average Power ◽  
Essential Element ◽  
Battery Life ◽  
Portable Devices ◽  
Clock Gating ◽  
Flip Flop ◽  
Content Type ◽  
Low Leakage

PurposeThe purpose of this paper is to design a low power clock gating technique using Galeor approach by assimilated with replica path pulse triggered flip flop (RP-PTFF).Design/methodology/approachIn the present scenario, the inclination of battery for portable devices has been increasing tremendously. Therefore, battery life has become an essential element for portable devices. To increase the battery life of portable devices such as communication devices, these have to be made with low power requirements. Hence, power consumption is one of the main issues in CMOS design. To reap a low-power battery with optimum delay constraints, a new methodology is proposed by using the advantages of a low leakage GALEOR approach. By integrating the proposed GALEOR technique with conventional PTFFs, a reduction in power consumption is achieved.FindingsThe design was implemented in mentor graphics EDA tools with 130 nm technology, and the proposed technique is compared with existing conventional PTFFs in terms of power consumption. The average power consumed by the proposed technique (RP-PTFF clock gating with the GALEOR technique) is reduced to 47 per cent compared to conventional PTFF for 100 per cent switching activity.Originality/valueThe study demonstrates that RP-PTFF with clock gating using the GALEOR approach is a design that is superior to the conventional PTFFs.

scholarly journals Comparative Study of Thyristor vs IGBT Based AC-DC Power Converter

2018 ◽  
Vol 17 (3) ◽  
pp. 89-102
Author(s):  
Md. Saiful Islam ◽  
Md. Rifat-Ul-Karim Shovon ◽  
Abdul Goffar Khan
Keyword(s):  
Comparative Study ◽  
Pulse Width ◽  
Output Voltage ◽  
Harmonic Distortion ◽  
Power Converter ◽  
Wave Shape ◽  
Average Output ◽  
Dc Power ◽  
Voltage Wave ◽  
The Relationship

This paper presents a comparative study of the application of Thyristor versus IGBT in AC-DC controlled power converter. Both simulation and practical experiment have been carried out to test the relationship between the average output voltage (Vdc) with firing angle (α, for Thyristor) and triggering pulse width (, for IGBT). Also the total harmonic distortion (THD) has been observed in both the cases. It is observed that IGBT based power converter introduces more harmonics in the system, in spite of more symmetrical output voltage wave shape.

scholarly journals Implantable Blood Pressure Sensors with Analogic Thermal Drift Compensation

2021 ◽  
Vol 6 (1) ◽  
pp. 34
Author(s):  
Serigne Modou Die Mbacke ◽  
Mohammed El Gibari ◽  
Benjamin Lauzier ◽  
Chantal Gautier ◽  
Hongwu Li
Keyword(s):  
Output Voltage ◽  
Pressure Sensors ◽  
Equivalent Model ◽  
Battery Life ◽  
Implantable Sensors ◽  
Thermal Drift ◽  
Research Activity ◽  
Drift Compensation ◽  
The Cost ◽  
Conditioning Circuit

Implantable pressure sensors represent an important part of the research activity in laboratories. Unfortunately, their use is limited by cost, autonomy and temperature-related drifts. The cost of use depends on several parameters, particularly their low battery life and the need for miniaturization to be able to implant the animals and monitor them over a time that is long enough to be physiologically relevant. This paper studied the possibility of reducing the thermal drift of implantable sensors. To quantify and compensate for the thermal drift, we developed the equivalent model of the piezoresistive probe by using the Cadence software. Our model takes into account the temperature (34–39 °C) as well as the pressure (0–300 mmHg). We were thus able to identify the source of the drift and thanks to our model, we were able to compensate for it thanks to the compensation circuits added to the conditioning circuits of the sensor. The maximum relative drift of the sensor is (0.1 mV/°C)/3.6 mV (2.7%), a drift of the conditioning circuit is (0.98 mV/°C)/916 mV (0.1%) and the whole is (13.4 mV/°C)/420 mV (32%). The compensated sensor shows a relative maximum drift of (0.371 mV/°C)/405 mV (0.09%). The output voltage remains stable over the measurement temperature range.

Power Consumption Characteristics of Appliances in a Smart House powered by Multi-Phase Transformer-based DC Power

2021 ◽  
Author(s):  
Kazuki Ikeda ◽  
Masaki Tsunekawa ◽  
Yuto Iwasaki ◽  
Kazuto Yukita ◽  
Toshiro Matsumura ◽  
...  
Keyword(s):  
Power Consumption ◽  
Dc Power ◽  
Smart House ◽  
Multi Phase

scholarly journals Inter-Stage Output Voltage Amplitude Improvement Circuit Integrated with Class-B Transmit Voltage Amplifier for Mobile Ultrasound Machines

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6244 ◽  
Author(s):  
Kiheum You ◽  
Hojong Choi
Keyword(s):  
Power Supply ◽  
Piezoelectric Transducer ◽  
Output Voltage ◽  
Piezoelectric Transducers ◽  
Voltage Amplitude ◽  
Voltage Amplifier ◽  
Class B ◽  
Voltage Signal ◽  
Limited Power ◽  
Limited Power Supply

Piezoelectric transducers are triggered by the output voltage signal of a transmit voltage amplifier (TVA). In mobile ultrasound instruments, the sensitivity of piezoelectric transducers is a critical parameter under limited power supply from portable batteries. Therefore, the enhancement of the output voltage amplitude of the amplifier under limited power supply could increase the sensitivity of the piezoelectric transducer. Several-stage TVAs are used to increase the voltage amplitude. However, inter-stage design issues between each TVA block may reduce the voltage amplitude and bandwidth because the electronic components of the amplifier are nonlinearly operated at the desired frequency ranges. To compensate for this effect, we propose a novel inter-stage output voltage amplitude improvement (OVAI) circuit integrated with a class-B TVA circuit. We performed fundamental A-mode pulse-echo tests using a 15-MHz immersion-type piezoelectric transducer to verify the design. The echo amplitude and bandwidth when using an inter-stage OVAI circuit integrated with a class-B TVA circuit (696 mVPP and 29.91%, respectively) were higher than those obtained when using only the class-B TVA circuit (576 mVPP and 24.21%, respectively). Therefore, the proposed OVAI circuit could be beneficial for increasing the output amplitude of the class-B TVA circuit for mobile ultrasound machines.

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