Transistor characteristics pdf. In the transistor, every three regions emitter, base, and emitter has a different width in the transistor. The purpose of this chapter is to review the fundamentals of MOS technology through the use of simplified models. Most of the equations presented in this chapter will not Sep 18, 2018 · Mobility Degradation. They are the building block for operational ampli er integrated circuits used in a wide array of linear and nonlinear circuit appli-cations. See full list on hunter. The BJT transistors have mainly three types of configurations. Voltage or current gain. 12, 2017 1 Purpose To measure and understand the common emitter transistor characteristic curves. L. VDD PMOS load line for VSG=VDD-VB. 3- DC Analysis of Active Mode BJT Circuits. NPN transistor is one of the Bipolar Junction Transistor (BJT) types. 1 Characteristics of an n-channel JFET The drain, or output, characteristics of ann-channel JFET are shown in figure 9. Emitter. To sign in to a Special Purpose Account (SPA) via a list, add a "+" to your CalNet ID (e. Fictional Resistance (no noise) Given an ideal BJT structure, we can model most of the action with the above circuit. The document provides information on the history and construction of transistors. To graph the collector characteristics of a transistor using experimental methods 3. A transistor is an electronic device that is used to allow one electrical signal to control another electrical signal, typically larger in either voltage or current. Oday A. MAXIMUM RATINGS. The emitter has the greatest level of doping, Nn ~ 1018/cm3 (recall that the number density of Si is 6 x1021/cm3), while that in the base is Np ~ 1016/cm3 and that in the collector is Nn ~ 1015/cm3. 7- Integrated Circuit Amplifiers. Several bipolar transistor models are introduced, i. 4- BJT as an Amplifier. Bipolar transistor fundamentals, 4. Unijunction transistors; silicon controlled rectifiers: characteristics and appl ications 5. Transistor is in common emitter configuration. Conventionally, 0. The The input and output characteristics of the transistor must first be examined in order to understand how a transistor works. The metal terminal is called the Gate. The bipolar transistors available in standard CMOS processes are described and compared. 4. microwave power transistor characterization into two. NPN Silicon. Applications fall into two groups: ampli ers and switches. Lab Exercises: Amplifier at Operating Point. 3MB) 11 Digital logic concepts, inverter characteristics, logic levels and noise margins, transient characteristics, inverter circuits, NMOS/resistor Depletion mode FETs have a channel implanted such that there is conduction with VGS=0. ec ≈ 5 × 104 V/cm for holes, hence velocity saturation for P-channel MOSFET will not become important until L < 0. It has three terminals an emitter (E) and two bases (B1 and B2). An NMOS has a lightly doped p-substrate (where there is scarcity of electrons). Leung, and R. pdf) or read online for free. Usually pick IC to be in the middle of the linear region. Subthreshold Leakage. The NPN transistor consists of two n-type semiconductor materials and they are separated by a thin layer of p-type semiconductor. cuny. Transistors characteristics are graphs of the various currents (Ibis current into the base, Ie is current out of the emitter, and Icis current into collector) and voltages. Figure. An input pulse of 0 to 5V amplitude is applied Jun 4, 2020 · Figure 2 shows a simple circuit. Uses 12 Volts for the battery voltage. 1) consists of a rod of n-type silicon to the ends of which ohmic (non rectifying)contacts Bl and B2 are made. DC and switching applications, 4. VB. Ahmed Example-2 A simple transistor switch is used to connect a 24V DC supply across a relay coil, which has a DC resistance of 200Ω. Therefore, determining transistor characteristics is one of the most basic experiments in an electronics laboratory. Transistor characteristics: Input characteristics Keeping the collector- emitter (VCE) voltage constant, the base- emitter (VBE) voltage is increased from 0 and the corresponding base current (IB) values are noted. •Pb−Free Packages are Available*. 3 Evaluation of Current–Voltage Characteristics of a Single Energy-Level Channel FET MOS transistors can be of two types- NMOS and PMOS. Mar 20, 2024 · NPN Transistor: Working, Input & Output Characteristics. The emitter is of p-type and it is heavily doped. 2N4400 is a general purpose NPN amplifier transistor. The three leads of a bipolar transistor are called the Emitter, Base, and Collector. 7 μm, x0 =0. Build the common emitter amplifier circuit using a 2N2222 transistor and RC = 1, 000 W, Re = 1, 000 W, R1 = 15, 000 W, and R2 = 9, 000 W. Body Effect. (a) characteristics of a MOSFET with L = 2. g. 5V V = 2V t RD K = 20m A ⁄ 2 n V. 3 °C/W Stresses exceeding Maximum Ratings may damage the device. Large-signal circuit models for the BJT are then introduced, to illustrate how one can analyze transistor circuits by using basic circuit The most important characteristics of transistor in any configuration are input and output characteristics. 85 N/GaN HEMTs. What is a Transistor? Classification of Transistors May 23, 2018 · IGBT is a short form of Insulated Gate Bipolar Transistor, combination of Bipolar Junction Transistor (BJT) and Metal oxide Field effect transistor (MOS-FET). Non-linear switch. Jun 6, 2017 · I–V characteristics for an Al 0. MOSFET physical structure, circuit symbol and terminal characteristics, MOS transistor characteristics 9 MOS transistor, backgate effect, MOSFET in saturation 10 MOSFET small-signal model (PDF - 1. The input characteristic resembles a forward biased diode curve. Collector−Emitter Voltage VCEO40 Vdc Collector−Base Voltage VCBO60 Vdc Emitter−Base Voltage VEBO6. It describes procedures conducted by a group of students to characterize transistors and analyze transistor bias Jun 16, 2023 · The CE transistor circuit provides medium input and output impedance levels. Figure 1 shows the transistor symbol for the npn transistor, pnp transistor and a schematic of TO-92 package transistor, with the pin connections identified for the BJT 2N4400. Now, the base emitter voltage V BE is varied and the corresponding base current I B readings are noted. 2N3055. Voltage biasing: The emitter-base junction of a PNP transistor must be forward-biased in order for current to flow. This means that current flows from the emitter to the collector, and out of the base. Transistor Characteristics and Single Transistor Ampli er February 10, 2023 1 Prelab Worksheet Note: Work out the exercises on this sheet before the lab. But When VIN = VDD, there is a direct current path between supply and ground. It’s is a semiconductor device used for switching related applications. After cut in voltage the I B The characteristic curves of a transistor provide the relationship between collector-emitter voltage and collector current for different values of the base current. 15 Ga 0. Figure 4. this is transistor material type file A Unijunction Transistor (UJT) is an electronic semiconductor device that has only one junction. doc), PDF File (. To determine the value of alpha and beta ratios of a transistor. Transistor means Transfer of Resistor. Sep 1, 2020 · Request PDF | Determining Transistor Characteristics with Arduino | Transistors are semiconductor devices that form the basis of today’s electronic technology. c currents and voltages of a transistor Such curves are known as static characteristics curves There are two important characteristics of a transistor Input characteristics Output characteristics INPUT CHARACTERISTICS Early effect as represented by the Early voltage. Transistor Characteristics and Bias (1) - Free download as Word Doc (. Estimate the delay of an inverter driving 4 identical inverters { Fanout-of-4 (FO4) delay An important abstraction at higher levels of the design d = 15RC. Below is Transistor Characteristics W. The circuit diagram for npn transistor is shown below. The drain characteristics are plots of drain current, I 0 , against V os• with Vas held constant at values here of 0, -1, -2 and -3 V. * In simple terms, a FET can be thought of as a resistance connected between S and D, which is a function of the gate voltage V G. ⇒ power is consumed even if the inverter is idle. Introduction. Apr 2, 2024 · The classification of transistors can be easily understood by observing the above tree diagram. 1 Unijunction transistors (UJTs) The unijunction transistor (Fig. Because there are two parameters that affect IC, a set of individual curves shown together denote various operating conditions. A bipolar transistor allows a small current injected at one of its terminals to control a much larger Mar 27, 2024 · The table which gives the main characteristics of a transistor in the three configurations is given above. General Purpose Transistors. If the system is a voltage-in, voltage-out system we would term this pseudo-static relationship the dc transfer characteristics. Jul 1, 2008 · As explained in this article, one can divide. Draw the load lines on the transistor characteristics 2. Transistor has three terminals emitter, base, and collector. Typical I-V characteristics of BJT for (a) common base and (b) common emitter configuration. To determine transistor type (npn, pnp),terminals, and material using a DMM 2. Inverter Delay Estimate, Cont'd. The document is a laboratory report for an electronics circuit analysis and design course. In the previous tutorial we saw that the standard Bipolar Transistor or BJT, comes in two basic forms. VA. The FET transistors are classified into JFET and MOSFET. NPN Transistors are three-terminal, three-layer devices that can function as either amplifiers or electronic switches. The goal of this text, as its name implies, is to allow the reader to become proficient in the analysis and design of circuits utilizing discrete semiconductor devices. Effects of velocity saturation on the MOSFET I-V characteristics. Outline of Chapter 5. , source (S) and drain (D). Three different transfer characteristics are shown in Fig. If IC = 2. Transistors used in electronic circuits fall into one of two categories: Linear amplifier. The Collector current and the voltage across the transistor (potential difference across the Collector and Emitter) can be measured. For low frequencies, we can forget the capacitors. Breakdown voltage given by BVCEO. H. Transistors that are fully “OFF” are said to be in their Cut-off region. HO: RF TRANSISTORS Among its other applications, transistors can be used to make Input characteristics of PNP transistor: E V constant EB i CB ûL ûY r Dynamic input resistance is given by – r i is very low (20 to 100 ) The input characteristics of NPN transistor are similar to those of PNP, differing only in that both i E and v EB would be negative and V CB would be positive. 1 volt to set VBE = - 0. Transistor switches can be used to switch and control lamps, relays or even motors. 3. Input Characteristics: ‐ It is the curve between input current I B and input voltage V BE constant collector emitter voltage V CE. Figures - uploaded by Navid Anjum Aadit VCE > 0. Among all these three configurations common-emitter configuration is mostly used type. In this circuit, we connect the collector to +5 V, the emitter to ground through a 220 Ω resistor and the base to a fixed value of 1 V. 02𝐾 4. areas: model extraction measur ements on the one hand. Y. Their most important non-idealities Aug 20, 2022 · • Assume ICBO is 100µA and RB is 100kΩ, then Required VBB is 10. Transistor has an application to work as a switch and as an amplifier and almost in all cases. 25 μm. BUH515. Transistor Characteristics and Single Transistor Ampli er Sept. In this chapter we shall take a close look at the electrical characteristics of the transistor, so as to be able to understand the circuit techniques which are discussed later on. Pin configuration for 2N4400 NPN transistor (upper left), NPN transistor A Simple Circuit for Measuring Transistor Characteristics As we said, bipolar transistors have three terminals: base, emitter, and collector. In contrast, a unipolar transistor, such as a field-effect transistor (FET), uses only one kind of charge carrier. ation of the bipolar junction transistor (BJT), which naturally follows the discussion of the pn junction in Chapter 9. To use the base current gain ( ), and load line analysis to predict and experimentally to verify the DC operating point (often called the \Q point") for your transistor in the The width of the electron flux “stream” is greater than the hole flux stream. The base is formed by lightly doped n-type bar of silicon. 3, together with the corresponding transfer characteristic. Functional operation above the Recommended Operating Conditions is not implied. The transistor characteristic under Common Collector configuration is as follows: Transistor Characteristics. txt) or view presentation slides online. 0 Vdc Collector Current − Continuous IC200 mAdc Total Device Dissipation @ TA= 25°C Derate In pnp transistors, the majority current carriers are holes. Integrated circuits typically contain millions of transistors, formed on a single tiny chip of silicon. 6- CEA, CEA with RE, CBA, & CCA. ☞ amp will respond the same way to symmetric (around operating point) output voltage swings. For input characteristics, the voltage 𝑉𝐶𝐸 were fixed and the voltage 𝑉𝐵𝐵 were varied and the Base current 𝐼𝐵 were calculated using 𝐼𝐵 = 𝑉𝐵𝐵−𝑉𝐵𝐸 10. The input voltage is varied which varies the Base current. In this article, while dealing with the general characteristics of transistors such as transistor construction, bias, load line, calculations related to bias and its applications in simple amplifiers, we also discuss how each one works. Definition. It must be turned in when you arrive for the lab and will be graded. 05 μm, Comparative theoretical characteristics computed (b) including velocity saturation 4 days ago · PNP transistor and NPN transistor. In small, discrete quantities, transistors can be used to create simple electronic switches, digital logic, and signal amplifying circuits. Transistors that are fully “ON” are said to be in their Saturation region. In a PNP transistor, the type of the layers are reversed. txt) or read online for free. T. DDU, Nadiad 22 Investigating transistor characteristics To understand how the npn bipolar transistor behaves, a simple circuit can be used. Channel Length Modulation. of EECS 10. - The dc beta (bDC) is the ratio of collector current (IC) to base current (IB) and represents the gain of a transistor. Note however, that we must use a controlled source, in May 14, 2008 · In this article, we will introduce you to measurements for power transistor characterization: why they matter, why they are such a complicated, highly specialized field, and where we think the technology of power transistor characterization is headed. March 20, 2024. The universal DC bias circuits 4. 5 mA and IB = 10-11 μA. 0 Objective In this lab, you will determine the IC - VCE characteristics of a BJT in several regions of operation. Physics of Heterostructures and High-Speed Transistors, 427 Material Properties and Processing of Semiconductor Materials and Heterostructures, 427 Problems, 428 6 FETs at Molecular Scales 429 6. pdf Description: This resource contains information on diodes, ideal diode model, full diode model, offset voltage model, half wave rectifier, full awve rectifier, and zener diode. For the input characteristics determine the Q point for the input circuit from the intersection of the load line and the characteristic curve (Note that some transistor do not need an input characteristic curve. Different Types of Field Effect, Bipolar Junction, Depletion, Enhancement, Insulated Gate Bipolar and Special Transistors. 4. SiGe transistor, transit time, and cutoff frequency are explained. Unlike MOSFETs, IGBTs do not have an intrinsic creverse diode, so inductive ringing, etc. The literature on MOS transistor characteristics is extensive. The circuit connections were made as shown in the above figure. 1 Volt 9/29/2021 Prof. Transistor provides linear gain. 2: Common base characteristics of the bipolar transistor. , can easily exceed the reverse voltage rating (e. You will then derive the large signal model for the BJT in each region Abstract. In this tutorial we'll introduce you to the basics of the most common transistor around: the bi-polar junction transistor (BJT). Download to read the full chapter text. transistor characteristics, the following steps apply: 1. Velocity Saturation. In quantities of thousands, millions, and even billions, transistors are The bipolar transistor uses one more layer of semiconductor material to produce a device with properties and characteristics of an amplfier. Figure 1. Two ohmic contacts B1 and B2 are attached at its ends. Yeung, W. Input Characteristics: These characteristics show how input current varies with input voltage for a constant output voltage, explaining the control behavior of transistors. ) 3. Collector. the theory of the bipolar transistor I-V characteristics, current gain, and output conductance. 5. If we join together two individual signal diodes back-to-back, this will give us two PN-junctions connected together in series which would share a common Positve , (P) or Negative , (N) terminal. Depending on what is added to the silicon, it will be either N-type or P-type. The next screen will show a drop-down list of all the SPAs you have permission to acc Apr 29, 2024 · Transistor Definition: Transistors are semiconductor devices used to amplify or switch electronic signals and electrical power. Maximum Ratings are stress ratings only. PNP transistor – PNP transistor is made up of two p-type and one n-type semiconductor. 5 is the linear region. Leakage. High Voltage (1500V) high power (50W) NPN fast switching transistor in an ISOWATT218 package, originally designed for use in analogue TV timebases but also used in switched mode power supplies. In the first quadrant, which is in the "forward active bias mode," the output from the collector terminal looks more or less like a current source; that is, IC I C is a constant, regardless of what VCB V CB is. 1 volt • If the transistor is replaced by the same type of transistor and new transistor is having I of transistor and new transistor is having ICBO few nA, then VBE will be approximately -10. Output Characteristics: This set of curves Reverse biased junction & Diffusion Capacitance. The transistor ranks as one of the greatest inventions of 20th century technology. of Kansas Dept. 2. The amount of current allowed between the collector and emitter . One can The rise time and the fall time are due to the fact that if a base-current step is used to saturate the transistor or return it from saturation to cuto , the transistor collector current must traverse the active region. 2. 26. B. By Ravi Teja. Relevant Measurements: hFE = IC/IB (DC Current Gain at VCE) hfe = Δ IC/ Δ IB (AC Current Gain at VCE) hoe = Δ IC/ Δ VCE (Conductance at IB) Create Tables for Various Parameters. 1. Here n region is as a base region. The experimental setup shown in Fig. BJT Operating Regions. The collector current increases or decreases along an exponential curve whose time constant Tr. 1 is studied in order to Fig. Measurements are taken of the output characteristic by varying collector voltage at constant base currents, and the transfer characteristic by varying base current at constant collector voltage. pdf), Text File (. In the electronic era, the development of the transistor is unquestionably one of the most valuable contributions in the field of Electronic components. Transistors are basically classified into two types. (a) NPN transistor symbol, (b) PNP transistor symbol and (c) TO-92 package 2N4400 BJT pin configuration. Greater than or less than unity. Transistor Characteristics ¶. doc / . 2N3903, 2N3904. The performance of transistors determined from their characteristic curves that relate different d. Electric field in the base-collector SCR extracts electrons into the collector. Constant charging current of load capacitance. To obtain maximum linearity of operation, the transistor must be kept within 4/30/2007 10_4 RF Transistor Characteristics 1/2 Jim Stiles The Univ. 5- BJT Small Signal Models. -IDp=IDn VDD. , Ebers–Moll model, small-signal model, and Notes on NPN transistors - David Kleinfeld - Spring 2018. Field-e ect transistors Source Drain Gate * A Field-E ect Transistor (FET) has a gate (G) terminal which controls the current ow between the other two terminals, viz. 1- Introduction to The Bipolar Junction Transistor. docx), PDF File (. Howe UC Berkeley EE 105 Fall 2005 1. This diagram is drawn to ease the understanding of the operation of the device, extending our earlier diode work. 65 V to 0. 1 FET: A Change of Paradigm, 430 6. The BJTs are again classified into NPN and PNP transistors. e. Electrical Engineering Department Power Transistors Characteristics Electrical Engineering Division Page 5 of 14 EG 405: Power Electronics Dr. Threshold Voltage Effects. The operating region of the transistor must be kept below this curve to avoid damaging the transistor. Rathod, EC Dept. Amplifiers: 4. noise margin with fast switching. Short Channel Effect. A. A graph of V BE against I B is plotted and Input resistance R i is calculated by drawing a The DC characteristics of BJTs can be presented in a variety of ways. Mar 13, 2024 · 26. The collector emitter voltage V CE is kept constant (say at 2volts). High Incremental resistance. A typical curve is shown in Figure 2a, and a set of CHARACTERISTICS OF BIPOLAR JUNCTION TRANSISTOR In addition to this instructions, please read the following chapters in the book ‘Basic electronics for scientists and engineers’ by D. The p-type substrate is grounded while the gate voltage VG is varied. Figure 2. Type/value of gain depends on surrounding circuitry. It finds application in virtually all electronic devices from radios to computers. The transistor is taken as the use of an amplifier because it gives proper biasing. Drain-Induced Barrier Lowering. The most useful and the one which contains the most information is the output characteristic, IC versus VCB and IC versus VCE shown in Fig. The forward voltage of the 2N3904 is 0. THERMAL CHARACTERISTICS Characteristic Symbol Max Unit Thermal Resistance, Junction to Ambient R JA 200 °C/W Thermal Resistance, Junction to Case R JC 83. edu Common Collector (CC) Configuration of Transistor. The text is intended for use in a first or second year course on semiconductors at the Associate or Baccalaureate level. They are used as am-pli ers in signal processing and as voltage-controlled switches. The characterization of microwave power transistors is an important and emerging field with many interesting engineering challenges. Holes are supplied by the base contact and diffuse across the emitter. Bipolar transistors consist of either a P-N-P or an N-P-N semiconductor “sandwich” structure. To use the base current gain ( ), and load line analysis to predict and experimentally to verify the DC operating point (often called the \Q point") for your transistor in the Bipolar Junction Transistors Emitter p n Collector Base pnp transistor Emitter n p Base npn transistor * Bipolar: both electrons and holes contribute to conduction * Junction: device includes two p-n junctions (as opposed to a \point-contact" transistor, the rst transistor) * Transistor: \transfer resistor" May 22, 2022 · 1. . Following the first step of The arrangement of transistors in electronic circuits is common emitter, common base and common collector. You will not be able to find those exact resistor values but get one as close as possible. W=1 micron L=1 microns Vt0= -2 volt Kp=2e-5 (A/v 2) Find the largest value that RD can have before the transistor fails to operate in saturation. ECE Department, University of Texas at Austin Lecture 4. An NPN transistor has a piece of P-type silicon (the base) sandwiched between two pieces of N-type (the collector and emitter). The i-v characteristics of bipolar transistors and their operating states are presented. The resistance Transistor Characteristics - Free download as PDF File (. High-level injection and heavy doping induced band narrowing are introduced. It discusses key developments in vacuum tubes from 1904 to 1947 that led to the invention of the transistor in 1947. The reverse injected holes recombine at the emitter ohmic contact. EXPERIMENT 6 REPORT Bipolar Junction Transistor (BJT) Characteristics. Forward active region. Mar 8, 2024 · A bipolar junction transistor is made up of three pieces of silicon. Each class can be The dotted hyperbola drawn on the output characteristics is the locus corresponding to the maximum power rating of the transistor given by Pc = V CE Ic. In order to make effective The DC characteristics of BJTs can be presented in a variety of ways. Rating Symbol Value Unit. This provides good performance and is frequently regarded as one of the most regularly utilised combinations. The document describes an experiment to investigate the characteristics of a transistor in a common emitter circuit. Features. 1: Basic configuration of NPN bipolar junction transistor. Jan 16, 2010 · The transfer characteristics of a system is defined to be the pseudo-static relationship between the input and output variable. 6. Transistor Characteristics 1 Motivation Like diodes, transistors are a fundamental element of modern electronics. A transistor is a semiconductor device used to amplify or switch electrical signals and power. The oxide layer (usually SiO2) is an insulator. The gate‐to‐source bias is swept from 1 to −2 V at a step of −1 V. In contrast, real BJTs are built in more of a “layer cake” fashion, N-P-N bottom to top 1. and model validation measurements on the 9. MOS Transistor Theory Jacob Abraham, September 8, 2020 31 / 31. When using the bipolar transistor as a switch they must be either “fully-OFF” or “fully-ON”. It progresses from basic diodes through bipolar and field effect transistors. 522-526 The most important and useful circuit element ever devised is the transistor. 2- Active Mode Operation of BJT. Transistor Characteristics and Parameters - Free download as Word Doc (. The large signal parameters will be determined experimentally. In CE Configuration, the Collector terminal of the transistor will be connected common between the output and the input terminals. , "+mycalnetid"), then enter your passphrase. It then describes the basic 1. They are: Bipolar Junction Transistors (BJT) and Field Effect Transistors (FET). Oct 13, 2023 · The following are some of the key characteristics of PNP transistors: Current flow: In a PNP transistor, the majority of charge carriers are holes. ☞ VCE = 5-6 V Can now choose the values for resistors (R1, R2) to give the above voltages and currents. If you have any problems with these exercises, please [see, call, email] the instructor well in advance of the lab. Here the majority charge carriers are the electrons. Graphs are plotted of collector current versus collector voltage and collector May 10, 2023 · The terminals of the transistor were identified. 17_diodes1. 2 2. Background ¶. There are two main classes of transistors: bipolar transistors and eld-e ect transistors. This chapter reviews the physics of bipolar transistors and the various effects that determine the temperature dependency of their base-emitter voltage. It is one of the basic building blocks of modern electronics. Transistors function as current regulators by allowing a small current to control a larger current. Objectives: 1. A selection of typical bipolar junction transistors (BJTs) is shown in Fig 3. 3 RF Transistor Characteristics Reading Assignment: pp. Bipolar transistors form the core of most smart temperature sensors. Input characteristics: 1. 1 4. Figure 3. L =. Capacitors are non-linear! MOS gate & overlap caps are linear. An NPN ( N egative- P ositive- N egative) configuration and a PNP ( P ositive- N egative- P ositive) configuration. 2 Resistance Redefined, 431 6. , 20 V). The bipolar junction transistor consists of three regions. [1] It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. The gain of both voltage and current can be characterised as a medium, however the output is 180 degrees out of phase with the input. 1. Eggleston: 4. Transistor Characteristics - Free download as PDF File (. Conservation of charge yields How to Sign In as a SPA. They are common-emitter, common-base and common-collector configurations. 7 V is used for calculations. 85 V at 10 mA collector current. A bipolar junction transistor ( BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. 3. A more accurate model to compute the voltage transfer function of an inverter will be introduced in Section 2. So it has the input characteristics of a MOSFET (zero dc gate current), combined with the output characteristics of a power bipolar transistor; note, however, that it cannot saturate toless than VBE. xy dq pc ja bj ov vc sx bb nq