Semiconductor Diodes
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Schottky Diodes Selection Guide
SCHOTTKY DIODES ( HOT - CARRIER ) pag A 1 Schottky diodes selection guide For HIGH SENSITIVITY , ZERO-BIAS or LOW BARRIER applications --- for lab detectors as RF detector with sweep generator --- RF fields detector, electromagnetic pollution, TAG , etc… --- passive or active mobile phones and bugs detector diode TSS Glass SMD Ceramic or special (tangential sensitivity) case case case HSMS 2850 - 2851 -59 dBm @ 2 GHz SMS 7630 -55 dBm @ 10 GHz these are the much sensitive diodes at usable up to 18 GHz ZERO BIAS -53 dBm @ 2 GHz ND 4991 - 1SS276 DDC2353 -55 dBm @ 6 GHz LOW BARRIER up to 20 GHz from -54 dBm to -52 dBm all BAT 15… types are LOW BARRIER up to 24 GHz depending on type high sensitivity vatious types available -56 dBm @ 2 GHz with bias HP 5082-2824 HSMS.282…series low barrier, up to millimeter freq. beam lead version version with leads of the famous 1N821 point-contact 1N21 - 23 silicon , up to 5 GHz NOTE : high sensitivity silicon or germanium diodes for detectors are available too, see VARIOUS DIODES for : RECEIVING MIXERS - RF DETECTORS - SAMPLING freq. config. glass case SMD or plastic case ceramic case up to 500 MHz BAT 42 - 43 - 46 - 48 - 85 - 86 BAS 40-…- BAT 64-.... 5082.2800 - BAT 45 - 82 - 83 single HSMS 28.... , BAT 68 up to HSCH 1001 2 GHz pair 5082.2804 BAS 70... , HSMS 28... quad 5082.2836 ND 487C1-3R 5082.2810, 2811, 2817 2824, up to HSMS 2810 , 2820 single 2835, 2900, MA4853 ND4991 BAT 17 , BAT 68 3 - 5 1SS154 ,BA 481, QSCH 5374 pair 5082.2826, 2912 HSMS 28…. -
Special Diodes 2113
CHAPTER54 Learning Objectives ➣ Zener Diode SPECIAL ➣ Voltage Regulation ➣ Zener Diode as Peak Clipper DIODES ➣ Meter Protection ➣ Zener Diode as a Reference Element ➣ Tunneling Effect ➣ Tunnel Diode ➣ Tunnel Diode Oscillator ➣ Varactor Diode ➣ PIN Diode ➣ Schottky Diode ➣ Step Recovery Diode ➣ Gunn Diode ➣ IMPATT Diode Ç A major application for zener diodes is voltage regulation in dc power supplies. Zener diode maintains a nearly constant dc voltage under the proper operating conditions. 2112 Electrical Technology 54.1. Zener Diode It is a reverse-biased heavily-doped silicon (or germanium) P-N junction diode which is oper- ated in the breakdown region where current is limited by both external resistance and power dissipa- tion of the diode. Silicon is perferred to Ge because of its higher temperature and current capability. As seen from Art. 52.3, when a diode breaks down, both Zener and avalanche effects are present although usually one or the other predominates depending on the value of reverse voltage. At reverse voltages less than 6 V, Zener effect predominates whereas above 6 V, avalanche effect is predomi- nant. Strictly speaking, the first one should be called Zener diode and the second one as avalanche diode but the general practice is to call both types as Zener diodes. Zener breakdown occurs due to breaking of covalent bonds by the strong electric field set up in the depletion region by the reverse voltage. It produces an extremely large number of electrons and holes which constitute the reverse saturation current (now called Zener current, Iz) whose value is limited only by the external resistance in the circuit. -
Thyristors.Pdf
THYRISTORS Electronic Devices, 9th edition © 2012 Pearson Education. Upper Saddle River, NJ, 07458. Thomas L. Floyd All rights reserved. Thyristors Thyristors are a class of semiconductor devices characterized by 4-layers of alternating p and n material. Four-layer devices act as either open or closed switches; for this reason, they are most frequently used in control applications. Some thyristors and their symbols are (a) 4-layer diode (b) SCR (c) Diac (d) Triac (e) SCS Electronic Devices, 9th edition © 2012 Pearson Education. Upper Saddle River, NJ, 07458. Thomas L. Floyd All rights reserved. The Four-Layer Diode The 4-layer diode (or Shockley diode) is a type of thyristor that acts something like an ordinary diode but conducts in the forward direction only after a certain anode to cathode voltage called the forward-breakover voltage is reached. The basic construction of a 4-layer diode and its schematic symbol are shown The 4-layer diode has two leads, labeled the anode (A) and the Anode (A) A cathode (K). p 1 n The symbol reminds you that it acts 2 p like a diode. It does not conduct 3 when it is reverse-biased. n Cathode (K) K Electronic Devices, 9th edition © 2012 Pearson Education. Upper Saddle River, NJ, 07458. Thomas L. Floyd All rights reserved. The Four-Layer Diode The concept of 4-layer devices is usually shown as an equivalent circuit of a pnp and an npn transistor. Ideally, these devices would not conduct, but when forward biased, if there is sufficient leakage current in the upper pnp device, it can act as base current to the lower npn device causing it to conduct and bringing both transistors into saturation. -
(Or Varicap) Diode
Radio and Electronics Cookbook 20 The varactor (or varicap) diode Introduction Many of the circuits for receivers and transmitters presented in this series rely upon the variable capacitor as a means of tuning. Another method of varying capacitance (without any moving parts) is provided by the varactor diode, sometimes called a varicap diode. This is a component which changes its capacitance as the voltage across it is varied. The details Figure 1 shows how a varactor diode might be connected to demonstrate its operation. Its symbol is that of an ordinary diode, with a capacitor symbol next to it. A variable voltage is applied across it in such a way that the diode is reverse-biased. This means that virtually no current passes through it – the positive voltage is applied to the cathode. Varactors are cheaper than variable capacitors, and they are tiny in comparison, very suitable for today’s miniature circuits. If A and B were connected across the tuning coil in a simple receiver (with a series capacitor to block the DC from the battery reaching the coil), the tuning operation would be accomplished by turning the knob on the 10 kilohm potentiometer. Varactors are available with different values, from less than 20 picofarad (pF) for VHF applications to 500 pF for medium-wave radios. They are Figure 1 The capacitance of the varicap diode (between A and B) increases as the voltage is reduced, using the variable resistor 64 A portable radio for medium waves tuned usually by voltages between 2 V and 9 V. For a real application of varactors, you should consult the circuit diagram of the Yearling 20 metre receiver, elsewhere in this book. -
J. W. Miller Company the Coil Forum March 1960
J. W. MILLER COMPANY-LOS ANGELES, CALIFORNIA-VOLUME 1, NUMBER 1 MARCH 1960 A TRANSISTOR FM RECEIVER With this issue, the J. W. Miller Company inaugurates a new publication devoted to the experimenter. Although coils, and their associated com ponents, are our business, we at Miller would like to supply our customers with timely information on circuits, theory to assist with your work or experiments, and data on how to select and use our coils wisely. We believe you will agree that THE COIL FORUM is indeed an appropriate nam~. www.SteamPoweredRadio.Com J. W. M I L L E R C O M P A N Y Recent advances in the state of the semiconductor from the collector back to the base through capacitor art have made it possible to construct a transistor Cl2 and the stage oscillates. Coil L3, along with the FM receiver which performs every bit as well as a tuning capacitor and circuit capacity, determines the vacuum tube version. VHF equipment places very frequency of oscillation, which is always 10. 7 me. strict demands on the transistors. They must be above the incoming signal frequency. Resistors R9 capable of constant amplification over the entire and Rl 1 provide bias and RIO is used for d.c. degener band being received, create a minimum of circuit ation. Transistor QlO and diode Xl are part of the drift, and provide maximum gain with a minimum automatic frequency control system and will be of stages. ' discussed later. All tuned circuits in the "front end" are tracked with a three-gang variable capacitor The excellent performance of the receiver to be (C3, 3-lOmmfd.) described is an outgrowth of the work done by Philco Corporation on their transistor "Safari" tele The i.f. -
68 Chapter 9: Thyristors Thyristors Thyristors Are a Class Of
Electronic Devices Chapter 9: Thyristors Thyristors Thyristors are a class of semiconductor devices characterized by 4-layers of alternating p- and n-material. Four-layer devices act as either open or closed switches; for this reason, they are most frequently used in control applications such as lamp dimmers, motor speed controls, ignition systems, charging circuits, etc. Thyristors include Shockley diode, silicon-controlled rectifier (SCR), diac and triac. They stay on once they are triggered, and will go off only if current is too low or when triggered off. Some thyristors and their symbols are in figure 1. (a) 4-layer diode (b) SCR (c) Diac (d) Triac (e) SCS Figure 1 Shockley Diode The 4-layer diode (or Shockley diode) is a type of thyristor that acts something like an ordinary diode but conducts in the forward direction only after a certain anode to cathode voltage called the forward-breakover voltage is reached. The basic construction of a 4-layer diode and its schematic symbol are shown in Figure 2. Figure 2: The 4-layer diode. The 4-layer diode has two leads, labeled the anode (A) and the cathode (K). The symbol reminds you that it acts like a diode. It does not conduct when it is reverse-biased. The concept of 4-layer devices is usually shown as an equivalent circuit of a pnp and an npn transistor. Ideally, these devices would not conduct, but when forward biased, if there is sufficient leakage current in the upper pnp device, it can act as base current to the lower npn device causing it to conduct and bringing both transistors into saturation 68 Assist. -
Capacitor & Capacitance
CAPACITOR & CAPACITANCE - TYPES Capacitor types Listed by di-electric material. A 12 pF 20 kV fixed vacuum capacitor Vacuum : Two metal, usually copper, electrodes are separated by a vacuum. The insulating envelope is usually glass or ceramic. Typically of low capacitance - 10 - 1000 pF and high voltage, up to tens of kilovolts, they are most often used in radio transmitters and other high voltage power devices. Both fixed and variable types are available. Vacuum variable capacitors can have a minimum to maximum capacitance ratio of up to 100, allowing any tuned circuit to cover a full decade of frequency. Vacuum is the most perfect of dielectrics with a zero loss tangent. This allows very high powers to be transmitted without significant loss and consequent heating. Air : Air dielectric capacitors consist of metal plates separated by an air gap. The metal plates, of which there may be many interleaved, are most often made of aluminium or silver-plated brass. Nearly all air dielectric capacitors are variable and are used in radio tuning circuits. Metallized plastic film: Made from high quality polymer film (usually polycarbonate, polystyrene, polypropylene, polyester (Mylar), and for high quality capacitors polysulfone), and metal foil or a layer of metal deposited on surface. They have good quality and stability, and are suitable for timer circuits. Suitable for high frequencies. Mica: Similar to metal film. Often high voltage. Suitable for high frequencies. Expensive. Excellent tolerance. Paper: Used for relatively high voltages. Now obsolete. Glass: Used for high voltages. Expensive. Stable temperature coefficient in a wide range of temperatures. Ceramic: Chips of alternating layers of metal and ceramic. -
Mcnearney, Eugene Master's Thesis
Analysis of Droplet-target interactions in electrostatically charged spraying systems A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, in Electrical and Electronic Engineering at the university of Canterbury by E. J. McNearney, B.E. Hons University of Canterbury, Christchurch, New Zealand December 2020. Abstract Increasing demands for food production and other agricultural products push demands for improved crop yields. Chemical pest management in the form of pesticides is a widely used method of increasing crop yields, over 90% of which is applied as liquid sprays. Poor application efficacy of these pesticides onto the target plant introduce concerns for both the environment and human health for those that come into contact. Traditional spraying techniques result in up to 70% off target losses, with less than 1% of the active chemical reaching the target pest. These losses are highly configuration dependent needing to be selected for the target plant and environmental conditions. One method to improve spray efficacy, electrostatically charging the liquid spray, has been previously introduced to market. This thesis has investigated factors influencing the liquid spray deposition onto the target, looking into plant impedances and using computer vision to quantify depositions with the ESS electrostatic nozzle. A high voltage power supply has also been developed to allow control of nozzle voltage. Leaf to ground impedances of potted grapevines were investigated as well as potential sources for the found values. It was found that the frequency and impedance relationship appears to follow dispersions found in other living tissues. It was also found that physical junctions in the plant where plant fibres intersect provided the largest impedance contributions with apparent linear regions in between. -
The Transistor
Chapter 1 The Transistor The searchfor solid-stateamplification led to the inventionof the transistor. It was immediatelyrecognized that majorefforts would be neededto understand transistorphenomena and to bring a developedsemiconductor technology to the marketplace.There followed a periodof intenseresearch and development, duringwhich manyproblems of devicedesign and fabrication, impurity control, reliability,cost, and manufacturabilitywere solved.An electronicsrevolution resulted,ushering in the eraof transistorradios and economicdigital computers, alongwith telecommunicationssystems that hadgreatly improved performance and that were lower in cost. The revolutioncaused by the transistoralso laid the foundationfor the next stage of electronicstechnology-that of silicon integratedcircuits, which promised to makeavailable to a massmarket infinitely more complexmemory and logicfunctions that could be organizedwith the aid of softwareinto powerfulcommunications systems. I. INVENTION OF THE TRANSISTOR 1.1 Research Leading to the Invention As World War II was drawing to an end, the research management of Bell Laboratories, led by then Vice President M. J. Kelly (later president of Bell Laboratories), was formulating plans for organizing its postwar basic research activities. Solid-state physics, physical electronics, and mi crowave high-frequency physics were especially to be emphasized. Within the solid-state domain, the decision was made to commit major research talent to semiconductors. The purpose of this research activity, according -
Voltage Doubler Circuit with 555 Timer
VOLTAGE DOUBLER CIRCUIT WITH 555 TIMER A Project report submitted in partial fulfilment of the requirements for the degree of B. Tech in Electrical Engineering By ASHFAQUE ARSHAD (11701614014) AKSHAY KUMAR (11701614005) DEBAYAN MANNA (11701614019) SURESH SAHU (11701614056) Under the supervision of MR. SUBHASIS BANERJEE Assistant Professor, Electrical Engineering, RCCIIT Department of Electrical Engineering RCC INSTITUTE OF INFORMATION TECHNOLOGY CANAL SOUTH ROAD, BELIAGHATA, KOLKATA – 700015, WEST BENGAL Maulana Abul Kalam Azad University of Technology (MAKAUT) © 2018 1 ACKNOWLEDGEMENT It is my great fortune that I have got opportunity to carry out this project work under the supervision of (Voltage Doubler Circuit with 555 Timer Circuit under the supervision of Mr. Subhasis Banerjee) in the Department of Electrical Engineering, RCC Institute of Information Technology (RCCIIT), Canal South Road, Beliaghata, Kolkata-700015, affiliated to Maulana Abul Kalam Azad University of Technology (MAKAUT), West Bengal, India. I express my sincere thanks and deepest sense of gratitude to my guide for his constant support, unparalleled guidance and limitless encouragement. I wish to convey my gratitude to Prof. (Dr.) Alok Kole, HOD, Department of Electrical Engineering, RCCIIT and to the authority of RCCIIT for providing all kinds of infrastructural facility towards the research work. I would also like to convey my gratitude to all the faculty members and staffs of the Department of Electrical Engineering, RCCIIT for their whole hearted cooperation -
Zero-Voltage Switching Flyback-Boost Converter with Voltage-Doubler Rectifier for High Step-Up Applications
Zero-Voltage Switching Flyback-Boost Converter with Voltage-Doubler Rectifier for High Step-up Applications Hyun-Wook Seong, Hyoung-Suk Kim, Ki-Bum Park, Gun-Woo Moon, and Myung-Joong Youn Department of Electrical Engineering, KAIST 373-1 Guseong-dong, Yuseong-gu, Daegeon, Republic of Korea, 305-701 [email protected] Abstract -- A zero-voltage switching (ZVS) flyback-boost (FB) output rectifier produces the high voltage spike. Thus, the converter with a voltage-doubler rectifier (VDR) has been snubber network is required across the output rectifier, which proposed. By combining the common part between a flyback results in a degraded efficiency. converter and a boost converter as a parallel-input/series-output As an attractive solution over aforementioned topologies, (PISO) configuration, this proposed circuit can increase a step- up ratio and clamp the surge voltage of switches. The secondary the flyback-boost (FB) converter was proposed as shown in VDR provides a further extended step-up ratio as well as its Fig. 1 [5], [6]. It can achieve a higher step-up ratio due to voltage stress to be clamped. An auxiliary switch instead of a both a transformer and a parallel-input/series-output (PISO) boost diode enables all switches to be turned on under ZVS configuration. Since the voltage spike across the switch is conditions. The zero-current turn-off of the secondary VDR limited to the output voltage of the boost converter, no alleviates its reverse-recovery losses. The operation principles, protection circuit is required. Furthermore, since the energy the theoretical analysis, and the design consideration are investigated. -
DESIGN and SIMULATION of a HIGH PERFORMANCE CMOS VOLTAGE DOUBLERS USING CHARGE REUSE TECHNIQUE 1. Introduction
Journal of Engineering Science and Technology Vol. 12, No. 12 (2017) 3344 - 3357 © School of Engineering, Taylor’s University DESIGN AND SIMULATION OF A HIGH PERFORMANCE CMOS VOLTAGE DOUBLERS USING CHARGE REUSE TECHNIQUE SHAMIL H. HUSSEIN Dept. of Electrical Engineering, College of Engineering, University of Mosul, Mosul, Iraq E-mail: [email protected] Abstract Voltage doubler (VD) structure plays an important role in charge pump (CP) circuits. It provides a voltages that is higher than the voltage of the power supply or a voltage of reverse polarity. In many applications such as the power IC and switched-capacitor transformers. This paper presents the design and analysis for VD using charge reuse technique CMOS 0.35µm tech. with high performance. Bootstrapped and charge reuse techniques is used to improve performance of integrated VD. Charge reusing method is based on equalizing the voltages of the pumping capacitances in each stage of CP. As a consequence, it reduces the load independent losses, improve the efficiency. Simulation using Orcad is applied for various VD structures shows improvement in charge reuse technique compared with existing counterpart. The results obtained show that the VD can be used in a wide band frequencies (0-100 MHz) or greater. The charge reuse VD circuit provided a good efficiency about (87.6%) and (83.5%) for one stage and two stage respectively at pump capacitance of 57pf, load current of 1mA, frequency of 10 MHz and supply voltage is 3.5 V compared with one stage and two stage of a latched VD are (85.4%) and (80%) respectively.