Darlington Transistor Research Articles

A Si-SiC Darlington Transistor Pair with Low Consumption

A Si-SiC Darlington Transistor Pair with Low Consumption

Fabrication and output performance of triboelectric nanogenerator from helical structure of biodegradable polylactic acid by 3D printing

In this study, a helical triboelectric nanogenerator (H-TENG) based on the helical structure of biodegradable polylactic acid was designed using 3D printing technology to achieve energy acquisition. When the H-TENG is pressed rhythmically with one hand, the output open-circuit voltage, short-circuit current and charge transfer density can reach 395 V, 28 μA and 36 μC/m2 respectively, which can light 300 LEDs in series. By connecting a simple rectifier and selecting a suitable capacitor, the H-TENG can independently and stably power portable electronic products, such as digital watches and calculators. Especially, as an electronic switch, the device enabled a high current amplification through the Darlington transistor circuit. These results demonstrated the potential applications of the H-TENG in biomechanical energy collection, sensing and human-machine interaction.

Computer simulation of a push-pull power amplifier

The paper presents the results of computer simulation of power amplifiers based on bipolar and complementary Darlington transistors. It is shown that the constant voltage gain is ensured by changing the current gain in the range from 103 to 105.

The design of a vehicle detector and counter system using inductive loop technology

Abstract Scheduling vehicles at multiple intersections remain an issue of concern in road traffic control. Traffic lights have been widely employed in many countries, however, determining the best intersection to grant access to using the number of vehicles present as a yardstick needs to be improved on. Therefore, this article presents the design of a vehicle detector and counter system using inductive loop technology. The proposed system is majorly made up of the inductive loop section, the electronic vehicle detector section and the counter section. The inductive loop uses an electromagnetic communication to create an electric current in a nearby wire, when a vehicle crosses the loop, the inductance of the loop is increased. Based on the oscillating signal received from the inductor loop, the electronic detector section uses a voltage comparator stage and Darlington transistor arrangement to detect the vehicles on the queue. Afterwards, two up-counters and an up/down counter were used to keep track of vehicles entering and leaving the queue. The design was simulated and tested in Proteus virtual system modelling software. The simulation results obtained revealed that the design could be employed for detecting and counting vehicles at intersections so as to effectively control traffic.

Specially Designed Multi-Functional Search And Rescue Robot

In digital era, robots are becoming an integral part of human life due to their efficiency and high performance. In recent years, search and rescue robot systems are used tremendously in a natural disaster. Nowadays, many areas of the world are getting affected due to natural disasters. Disasters can be exceptional and unstoppable events that are either man-made or natural, such as building collapse, earthquakes, wildfires, and floods, etc. This witnesses the importance of search and rescue robot systems in the emergency field. In the emergency field, a variety of sensing and wireless technologies are used in remote and vision control. The use of these technologies, the rescuers instead of going inside in the ruined area, can control remotely search and rescue robot systems when natural calamity occurs. These robot systems have the ability to move and monitor in the ruined area as a result of natural disasters such as building collapse, earthquakes, wildfires, and floods. In this paper, we design a sensor-based multi-functional search and rescue robot system for use in emergency situations. The system consists of an Arduino Mega board, Raspberry Pi 3 Model B+ board, servo motor, camera, Direct Current motor, motor driver module, stepper motor, Darlington Transistor Arrays, and ultrasonic sensor. The multi-functional search and rescue robot system has the ability to help the rescuers to search and show the ruined area from far away. The rescuers also could save their lives using this robot system. The main objective of this paper is to design a multi-functional, easy to control, microcontroller and Vision control based rescue robot system.

Use of Arduino in the Development of a New and Fast Automated Online Preconcentration System Based on Double-Knotted Reactor for the Mn Determination in Tea Samples by Flame Atomic Absorption Spectrometry (F AAS)

In the present paper, an automated online preconcentration system based on the use of two knotted reactors (KR) was developed for Mn determination in tea samples by flame atomic absorption spectrometry (F AAS). The system automation was performed by using four solenoid valves to switch sample streams and reagents. Valves were driven electronically by an integrated Darlington transistor circuit and controlled by an open-source Arduino hardware platform written in C language. The preconcentration was based on the precipitation process of metal ions complexed with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (5-Br-PADAP) on the inner walls of the reactor, followed by elution with a solution of hydrochloric acid. The optimized system allowed the Mn determination with limit of detection (LOD) of 2.1 mg L-1, precision (relative standard deviation (RSD), 50.0 mg L-1) of 2.6% and enrichment factors of 8. The system presented a sampling frequency of 60 h-1. The method accuracy was evaluated by analysis of the certified reference material (CRM) apple leaves (NIST 1515) and by addition/recovery tests obtaining recoveries between 95.2 to 119%. This method was applied in the Mn determination in commercial tea samples purchased from local trade. Manganese levels were found in a concentration range of 2.95 to 123 µg g-1.

The influence of pulsed parameters on the damage of a Darlington transistor * * Project supported by the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (No. 2015-0214.XY.K).

Theoretical research on the heat accumulation effect of a Darlington transistor induced by high power microwave is conducted, and temperature variation as functions of pulse repetitive frequency (PRF) and duty cycle (DC) are studied. According to the distribution of the electronic field and the current density in the Darlington transistor, the research of the damage mechanism is carried out. The results show that for repetitive pulses with the same pulse widths and different PRFs, the value of temperature variation increases with PRF increases, and the peak temperature has almost no change when PRF is lower than 200 kHz; while for the repetitive pulses with the same PRF and different pulse widths, the larger the pulse width is, the greater temperature variation varies. The response of the peak temperature caused by a single pulse demonstrates that there is no temperature variation when the rising time is much shorter than the falling time. In addition, the relationship between the temperature variation and the time during the rising edge time as well as that between the temperature variation and the time during the falling edge time are obtained utilizing the curve fitting method. Finally, for a certain average power, with DC increases the value of temperature variation decreases.

Method for Building Health Index of Darlington Transistor Based on KPCA and Mahalanobis Distance

In order to obtain characteristic parameters which can describe the healthy status of Darlington transistor, a method for building Health Index (HI) based on KPCA and Mahalanobis distance was proposed. Through the failure mechanism analysis and Accelerated Degradation Testing (ADT) of Darlington transistor, the degradation data of collector current and saturation voltage were obtained. For the degradation data has obvious nonlinear features and some noise which are unfavorable for failure analysis, a data processing method was put forward by using wavelet packet decomposition and Kernel Component Analysis (KPCA). The interference signal was filtered and the main components were obtained. By using this method. Finally, the Mahalanobis distance was used to fuse these components into Health Index. And the Health Index could represent how the healthy status of Darlington transistor changes. Through multiple sets of data verification, the Health Index used Mahalanobis distance showed higher prediction accuracy than the Euclidean distance with the same fault predict algorithm.

4H-SiC monolithic Darlington transistors with slight current gain drop at high collector current density

Profit from high current gain features, 4H-SiC power Darlington transistor has the capacity for handling high current transmission. In this paper, monolithic Darlington transistors were fabricated using a simultaneous formation process for both n-type (emitter) and p-type (base) ohmic contact. The isolated device shows current gain of 1061 and 823 with collector current density ( J C) increasing from 200 to 800 A/cm2, exhibiting a slight current gain drop at high J C. By extracting the interface state density ( D it) between SiO2 and p-type 4H-SiC, it is found that this advantage owes to the improvement of the shallow bulk minority carrier lifetime in base region. Furthermore, ISE-TCAD (technology computer aided design) simulation was carried out to study the relationship between base minority lifetime and the current gain, from which the total base minority lifetime is estimated to be 48 ns. The open base breakdown voltage ( BV CEO) is 850 V at a leakage current of 2 μA due to the electric filed crowding at the isolation bottom between drive bipolar junction transistor (BJT) and output BJT. To solve this, non-isolated devices were also fabricated with improved BV CEO of 2370 V, indicating the superior potential of 4H-SiC monolithic Darlington transistors for high power application, while the current gain is deceased to 420, which needs further improvement.

Driver for 5-phase stepper motor pentagon connection with dedicated ICs

Stepper motors are very well suited for positioning applications since they can achieve very good positional accuracy without complicated feedback loops associated with servo systems. In this paper, an intelligent five-phase stepper motor driver of business card size proposed. Constant current chopping technique was applied for the purposes of high torque, high velocity and high efficiency. The driver was designed to drive a middle-sized hybrid stepper motor with wire current rating from 0.7 to 1.4A. An up-to-dated translator of five-phase stepping motor was used to drive the gates of N- channel MOSFET (Low side N-channel MOSFET Array) and level shift for NPN Darlington transistor (High side PNP Darlington transistor). The resolution in full/half mode is 0.72/0.36 degrees/step. Moreover, an automatic power down circuit was used to limit the power consuming as the motor stops. Additionally, a self-testing program embedded in an 80C31-CPU (PCL838) can self-test whether the driver is normal or not. This embedded program including linear acceleration and deceleration routines also can serve as a positioning controller. The dimension of this driver is approximate 90x70x40 millimeters, which is smaller than a business card. Experimental results demonstrate that the responses of the driver can reach 60 kilo pulses per second.

Failure analysis of solder layer in power transistor

PurposeThe purpose of this paper is to present a failure analysis of the solder layer in a Darlington power transistor in a TO-3 package.Design/methodology/approachA failed Darlington power transistor in a TO-3 package was examined by different kinds of failure analysis techniques. At first, internal gas analysis was conducted to measure the atmosphere. Then, scanning acoustic microscopy (SAM) was performed to check the quality of the solder layers in the failed device, and the failure location was determined in the solder layer between chip and substrate. Next, the failed device was decapped to observe the defects. After removing the chip from the substrate, energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were applied and the main elemental composition of the solder layer was identified.FindingsInternal gas analysis indicated that the moisture and oxygen contents exceeded the allowed maximum value. Large areas of voids were found in the solder layer by SAM. The main elemental compositions of the solder layer were identified by scanning electron microscopy and EDS. Furthermore, the valences of the chemical components in the solder layer were identified by XPS. Except for the few simple substances of the initial solder material, the chemical formulae of oxidation products in the solder layer were deduced. In addition, the root causes are also discussed.Originality/valueThis paper focuses on the solder layer failure of a power transistor. Factors such as the presence of oxygen, voids and other factors, which can cause transistor damage, were comprehensively analyzed. The analysis process is worth learning from and the results can be used to improve the reliability of power devices in this kind of package.

Design and Characterization of High-Current Optical Darlington Transistor for Pulsed-Power Applications

A high-current and low on-state voltage optical Darlington transistor (ODT) is developed in this paper for high-power applications. The structure of this device includes a two-stage Darlington transistor in which the first stage is triggered optically using an infrared laser of an 808-nm wavelength. The photogenerated current in the first stage drives the second stage of the ODT for current amplification. The ON-state voltage of the proposed two-stage ODT is found to be 1.12 V at 50 A. The results show that a single-pipe laser with a low optical power of 2 W is sufficient to trigger this high-current optical switch. This can give us more flexibility to achieve an optimal tradeoff between the ON-state voltage and delay times. The experimental results show that the ODT has a breakdown voltage of 70 V and can operate at frequencies higher than 10 kHz. Thismakes it potentiallysuitable as an optical gate driver for applications including but not limited to pulsed-power and series-connectionof power semiconductor devices for voltage scaling, and as an auxiliary optical-triggering device for anode- or even gate-currentmodulation of a high-frequency and high-power all-optical emitter turn-OFF thyristor.

Intertwined Design: A Novel Lithographic Method to Realize Area Efficient High-Voltage SiC BJTs and Darlington Transistors

A novel lithographic method called intertwined design is demonstrated for high-power SiC devices to improve the area usage and current drive with more uniform current distribution along the device. The higher current drive is achieved by employing the inactive area underneath the base metal contact pads; more uniform current distribution is obtained by the center-base design; whereas the hexagon and square cell geometries result in >15% higher current density at lower on-resistance compared with the conventional finger design. For the first time, we have experimentally presented the intertwined design to marry these advantages and realize a high-efficient SiC power device. Center-base high-voltage 4H–SiC BJTs and Darlington pairs with different square and hexagon cell geometries are fabricated and compared with conventional designs to prove the ability of the intertwined design. The method can widely be used for large-area high-voltage BJTs as well as for integrated devices.

An alternative method for using bipolar junction transistors as a radiation dosimetry detector in breast cancer treatment

Silicon photodetectors and MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) are frequently used devices for measuring ionizing radiation in health physics instrumentation. The Bipolar Junction Transistor (BJT) is not a typical device used as a detector for measuring some physical quantities in radiotherapy beams due to its loss of sensitivity to ionizing radiation, as a consequence of radiation damage in the silicon semiconductor substrate. Actually, the know-how of the BJT characteristic curves and its response to ionizing radiation leads us to suggest an alternative method to estimate the radiation dose value in breast cancer treatments. The BJT parameter to be evaluated before and after the irradiation procedure is the BJT amplification factor, also called DC gain β. In this work, the study was done using a BJT known as Darlington type, within an Alderson Rando anthropomorphic phantom. Darlington transistors have very high gain and this feature allowed that the BJT gain changes to be correlated with the dose of the radiation beam. The results indicate that this new method could be an alternative option to estimate the dose value in the phantom for measurements in breast cancer radiotherapy.

고속 전원차단 회로 설계 제작 및 측정

In this paper, a design of high-speed power-off circuit and analysis. The incidence of high-dose transient radiation into the silicon-based semiconductor element induces the photocurrent due to the creation of electron-hole pairs, which causes the upset phenomenon of active elements or triggers the parasitic thyristor in the element, resulting in latch-up. High speed power-off circuit was designed to prevent burn-out of electronic device caused by Latch-up. The proposed high speed power-off circuit was configured with the darlington transistor and photocoupler so that the power was interrupted and recovered without the need for an additional circuit, in order to improve the existing problem of SCR off when using the thyristor. The discharge speed of the high speed power interruption circuit was measured to be 19 ㎲ with 10 ㎌ and 500 Ω load, which was 98% shorter than before (12.8 ㎳).

High-Temperature Characterization of 4H-SiC Darlington Transistors for Low Voltage Applications

4H-SiC bipolar Darlington transistors (D-BJTs) for low voltage applications have been fabricated, simulated and characterized up to 300 °C, where they exhibit a current gain of 460. The influence on D-BJT current gain of relative current capability of driver and output BJTs has been investigated, and the collector resistance has been identified as the main limitation for the D-BJTs.

Design of Low Voltage, Low Power (IF) Amplifier Based-On MOSFET Darlington Configuration

This paper presents a different approach of Intermediate Frequency (IF) amplifier using 0.18 μm MIETEC technology channel length of MOSFET Darlington transistors. In contrast to Bipolar conventional Darlingtonpair, a MOSFET Darlington configuration is employed to reduce supply voltage (VDD) and DC consumption power (Pc). The frequency response parameters of the proposed design such as bandwidth, gain bandwidth product, input/output noises and noise figure (NF) are improved in proposed (IF) amplifier. Moreover, a dual-input and dual-output (DIDO) IF amplifier constructed from two symmetrical single input and single output (SISO) (IF) amplifier is proposed too. The idea is to achieve improved bandwidth, and flat response, because these parameters are very important in high frequency applications. Simulation results that obtained by P-SPICE program are 1.2 GHz Bandwidth (BW), 3.4 GHz (gain bandwidth product), 0.5 mW DC consumption power (Pc) and the low total output noise is 12 nV with 1.2 V single supply voltage.

High Current-Gain Implantation-Free 4H-SiC Monolithic Darlington Transistor

An implantation-free 4H-SiC Darlington transistor with high current gain of 2900 (J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> = 970 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CE</sub> = 6 V) at room temperature is reported. The device demonstrates a record maximum current gain of 640 at 200°C, offering an attractive solution for high-temperature applications. The monolithic Darlington device exhibits an open-base breakdown voltage of 1 kV that is less than the optimum bulk breakdown due to isolation trench between the driver and the output bipolar junction transistor. On the same wafer, a monolithic Darlington pair with a nonisolated base layer was also fabricated. At room temperature, this device shows a maximum current gain of 1000 and an open-base breakdown voltage of 2.8 kV, which is 75% of the parallel-plane breakdown voltage.

10 kV, 10 A Bipolar Junction Transistors and Darlington Transistors on 4H-SiC

4H-SiC Bipolar Junction Transistors (BJTs) and hybrid Darlington Transistors with 10 kV/10 A capability have been demonstrated for the first time. The SiC BJT (chip size: 0.75 cm2 with an active area of 0.336 cm2) conducts a collector current of 10 A (~ 30 A/cm2) with a forward voltage drop of 4.0 V (forced current gain βforced: 20) corresponding to a specific on-resistance of ~ 130 mΩ•cm2 at 25°C. The DC current gain, β, at a collector voltage of 15 V is measured to be 28 at a base current of 1 A. Both open emitter breakdown voltage (BVCBO) and open base breakdown voltage (BVCEO) of ~10 kV have been achieved. The 10 kV SiC Darlington transistor pair consists of a 10 A SiC BJT as the output device and a 1 A SiC BJT as the driver. The forward voltage drop of 4.5 V is measured at 10 A of collector current. The DC forced current gain at the collector voltage of 5.0 V was measured to be 440 at room temperature.

A 10-kV Monolithic Darlington Transistor With $\beta_{ \rm forced}$ of 336 in 4H-SiC

4H-SiC bipolar Darlington transistors with a record-high current gain have been demonstrated. The dc forced current gain was measured up to 336 at 200 W/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> = 35 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CE</sub> = 5.7 V) at room temperature. The current gain exhibits a negative temperature coefficient and remains as high as 135 at 200degC. The specific on-resistance is 140 mOmegamiddotcm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at room temperature and increases at elevated temperatures. An open-emitter breakdown voltage ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BV</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CBO</sub> ) of 10 kV was achieved at a leakage current density of < 1 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The device exhibits an open-base breakdown voltage ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BV</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CEO</sub> ) of 9.5 kV. The high current gain of SiC Darlington transistors can significantly reduce the gate-drive power consumption with the same forward-voltage drop as that of 10-kV SiC bipolar junction transistors, thus making the device attractive for high-power high-temperature applications.