Measure the voltage gain of the amplifier to see how it compares with your calculated voltage gain. Feb 19, 2017 in this session,we explained about electronics and communication engineering lab experiment rccoupled amplifier. You will not be able to find those exact resistor values but get one as close as possible. It is the most common amplifier configuration of allit is found in analog and digital circuits, from dc. How to draw ce amplifier circuit using multisim software.
The single stage common emitter amplifier circuit shown above uses what is commonly called voltage divider biasing. Cascaded common emitter swamped amplifier experiment. Design the amplifier for voltage gain a v to be at a minimum of 100 vv and choose resistor values of r c and r e by calculation. There are additionally three capacitors but they do not play a role in the basic transistor amplifier design which mainly involves setting dc voltages.
A common base and a common collector amplifier will be designed and tested. There are three basic singlestage amplifier configurations using. This article discusses the working of the common emitter amplifier circuit and its applications. Circuits laboratory experiment 9 operational amplifiers 9. Figure 1 gives the basic circuit of ce amplifier using npn transistor bias through use of resistor r b. In this circuit the base terminal of the transistor serves as the input, the collector is the output, and the emitter is common to both for example, it may be tied to ground. The gain is a strong function of both temperature and bias current, and so the actual gain is somewhat unpredictable. The cs mosfet amplifiers can be compared to the ce bjt amplifiers respectively. We will also plot the output characteristics curves commonly associated with amplifier circuits as a function of the collector current to the base current. Class a bjt amplifiers this worksheet and all related files. The curve drawn between voltage gain and the signal frequency of an amplifier is known as frequency response. Common emitter ce amplifier operating point engineering. High frequency response of the ce and er amplifier the generic commonemitter amplifier circuit of section d2 is reproduced to the left below and the small signal circuit using the high frequency bjt model is given below right based on figures 10. We will first explain the circuit, show its results on orcad.
We will first take up the basic working of a singlestage amplifier i. The purpose of this lab is to understand how to design bjt amplifiers in the commonemitter, commonbase and commoncollector configurations. Due to miller effect the amplifiers with increased gain demonstrate decreased bandwidth. This type of biasing arrangement uses two resistors as a potential divider network across the supply with their center point supplying the required base bias voltage to the transistor. Generally, they use an alphanumeric marking system. Measure dc operating voltages at each circuit nodes, voltage gain, input, output impedance of the amplifier and compare the values to the prelab. The voltage gain and frequency response of the ce amplifier are obtained. Drive the input with small sinusoidal signal output should not exceed 1 v and measure the values of the design parameters. Frequency response curve the curve representing the variation of gain of an amplifier with frequency is. It is called a common emitter amplifier since the emitter is common to both the input circuti and the output circuit. Rcphase shift oscillator has a ce amplifier followed by three sections of rc phase shift feedback networks.
The first input is called inverting represented by, and the other terminal is called noninverting input. Ceramic capacitors are generally nonpolarized and almost as common as radial electrolytic capacitors. Frequency response of a commonemitter bjt amplifier analog. This report attempts to characterize the common emitter amplifier circuit by explaining the theoretical basis and simulating the circuit in the. Circuit description of common emitter ce amplifier. Characteristics of a ce amplifier a ce transistor amplifier has the following characteristics. For the amplifier circuit shown above, students will draw the dc equivalent circuit and calculate the following dc quantities. Ecen 326 lab 1 design of a commonemitter bjt ampli. The frequency response will be measured and the dc voltages will be compared to calculated values.
In this prelab, you will explore the design of a single stage ampli. Ph 210 electronics laboratory i instruction manual index page no general instructions 2 experiment 1 common emitter ce amplifier 4 experiment 2 multistage amplifier. Mar 23, 2016 simulation of inverting amplifier in multisim duration. Have your data sheet checked off by your ta before leaving the lab. The basic transistor amplifier circuit is indicated below.
Determine the amplifier load line and find the dc operating point qpoint. Lets start our discussion on common emitter amplifier ce amp, rather from the first bjt lab, in which we discussed about base voltage and collector voltage in the operating region. The commonemitter ce transistor amplifier configuration is widely used. Experiment 6 transistors as amplifiers and switches. Bjt amplifiers 6 chapter outline 61 amplifier operation 62 transistor ac models 63 the commonemitter amplifier 64 the commoncollector amplifier 65 the commonbase amplifier 66 multistage amplifiers 67 the differential amplifier 68 troubleshooting device application chapter objectives describe amplifier operation discuss transistor models. Like the ce amplifier, the cs amplifier has negative voltage gain and output impedance approximately equal to the drain resistor in parallel with mosfet drain to source resistance rd ro. The latter capacitance between base and collector gives rise to so called miller effect. A manual for undergrad students teaching staff article pdf available august 2015 with 16,574 reads how we measure reads. It is because reactances of the capacitors in the circuit changes with signal frequency and hence affects the output voltage. With proper biasing, we can use it as a current amplifier ca, voltage amplifier va, transconductance anplifiertca as well as transresistance amplifier tra. In a common emitter configuration, emitter is common to both input and output as shown in.
To measure av l and av 0, we apply a sinusoidal input voltage1 vs in fig. Calculate voltage gain and bandwidth of ce amplifier from the observations made. Circuits laboratory experiment 9 operational amplifiers. Commonemitter amplifier vsupply 1 0 dc 12 vin 3 0 rc 1 2 10k rb 3 4 100k q1 2 4 0 mod1. When the amplifier is attached a small load, what effect does it have on the gain. It is called a common emitter amplifier since the emitter is common to both the input circuti and the output.
Measure the output resistance r o of the amplifier looking into the output port. Once we have these basic amplifier configurations under our belt, we will then. The parameter analyzer supplies a similar set of files with data for lab 2, and labs 1 and 6 require making plots and fft calculations from a digital oscilloscope. In a commonemitter ce amplifier, the input signal is applied between the. Measure the voltage gain of the amplifier to see how it compares with your. Common emitter amplifier circuit working and characteristics. Common emitter 1 objective design and analysis of analog ampli. Capacitors c b and c c are used to block the amplifier dc bias point from the input and output ac coupling. Objectives study and characterize bjt amplifier in common emitter ce configuration. Topics to cover family of singlestage bjt amplifiers. Electrical machine ii lab 09study of common emitter amplifier and. The number part is the same as for smt resistors, except that the value represented is in pf. What conclusion can you draw about the type of load that a commonemitter amplifier. In this experiment we will build a twostage amplifier using two bipolar.
You will be using a 2n2222 transistor so your data will be different. Miller capacitor c f is a small capacitance that will be used to control the high frequency 3db response of the amplifier. 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. Be aware if the text says commonemitter, but there is no emitter cap, it is an emitterresistor. Also gain bandwidth product of the amplifier is calculated. The common emitter amplifier is one of the three basic transistor amplifier configurations. A generic commonemitter ce amplifier circuit is shown to the right this is a modified representation of figure 5. Frequency response of commonemitter ampli er theory the circuit diagram the commonemitter ce ampli er is shown in fig. Eed2012 analog electronics 20 spring experiment 4 vin c1 r2 r1 rd c2 rl rs c3 vdd vout figure 1. Gainbandwidth product gbw in ce amplifies remains approximately constant. When the amplifier is attached a load comparable to r c, what effect does it have on the gain. A bjt common emitter amplifier contents of tables and figures. Frequency response of commonemitter ampli er theory.
This will result in vin having an amplitude of 10 mv due to the 10. Experiment 3 common emitter amplifier amplifier electrical. If the signal is 1800 out of phase and gain will be 1. Design and analyze ce amplifier using multisim software. Study aids, multisim, and lt spice files for this chapter are available at. What we really care about for these devices is what useful functions they can actually perform and, to. Cascade of two ce stages 7 experiment 3 push pull amplifier 9 experiment 4 op amp circuits 11 experiment 5 filter circuits feed back circuit. Ce amplifier r 1 vs rc v rl o r 1 r 2 rc rl cb cc re ce r 2 vs vo vbe gmvbe vbe e b c ro r. Capacitor c e is an ac bypass capacitor used to establish a low frequency ac ground at the emitter of q 1. No name of the experiment 1 common emitter amplifier 2 common source amplifier 3 two stage rc coupled amplifier 4 current shunt feedback amplifier 5 cascode amplifier 6 colpitts oscillato 7 rc phase shift oscillator using transistors 8 classa power amplifier transformer less 9 class b complementary symmetry amplifier. Construct common emitter ce amplifiers simulated in the prelab analysis.
Determine what would happen to the voltage gain of a commonemitter transistor amplifier circuit if the following resistance values were. The common source is the most commonly used mosfet ampli. Figure 1 cascaded common emitter swamped amplifier ewb version 5 voltage gain calculations. The purpose of biasing is to establish a qpoint about which variations in current and voltage can occur in response. Commonemitterce and commonsourcecs are the two most widely used con. Common emitter amplifiers are the most widely used form of bjt in amplifier.
V2 should equal a 100mv pk ac voltage centered at 0v. The frequency response is a graphical representation of the relationship between. Frequency response of common collector amplifier objective the purpose of the experiment is to analyze and plot the frequency response of a common collector amplifier. To visualize the operation of a transistor in an amplifier circuit, it is often useful to represent the. The inverting amplifier an example of shunt shunt feedback amplifier and feedback network have same input and output port voltages input current to the amplifier is the sum the mixture of input and feedback path currents. Common emitter amplifier working principle and its. To study the frequency response and bandwidth of the common emitter cebjt, the common collector ccbjt, and the common base cbbjt amplifiers. The object is to solve for the smallsignal voltage gain, input resistance, and output resistance. It is assumed that the student has had some background in transistor amplifier theory, including the use of ac equivalent circuits. Since an integrated circuit is constructed primarily from dozens to even millions of transistors formed from a single, thin silicon crystal, it.
Pdf a bjt common emitter amplifier contents of tables. Set the signal source to have an amplitude of 100 mv at f 10 khz. The data below were collected for the example of a npn 2n36443 transistor using the circuit below. It provides large voltage gain typically tens to hundreds and provides moderate input and output impedance. Commonemitter amplifier is constructed using fixed bias circuit. Operational amplifier op amp is a three terminal electronic device which has two inputs of high impedance. The feedback network samples the output voltage and contributes a current to correct the input.
Here capacitor c b1, acts as the coupling capacitor to couple the input signal to the basetoemitter terminals of the transistor. Bode plots of firstorder lowpass filters include one capacitor display. The voltage gain of a ce amplifier varies with signal frequency. The ta still has to witness the measurement and issue the id number, and in doing so will check your circuit board serial. Objective the purpose of these experiments is to introduce the most important of all analog building blocks, the operational amplifier opamp for short. In this experiment, the student will build and investigate a basic npn common emitter transistor amplifier. In this experiment, transistor type 2n3904 is used. Commonemitter amplifiers are also used in radio frequency transceiver circuits. To calculate this, we need rtc1, which requires us to know rib2. The capacitor cb is used to couple the input signal to the input port of the ampli.
Construct common base cb amplifier simulated in the prelab analysis 2. There are different types of electronic components in the common emitter amplifier which are r1 resistor is used for the forward bias, the r2 resistor is used for the development of bias, the rl resistor is used at the output it is called as the load resistance. To design and construct a common emitter amplifier circuit and to determine its bandwidth and. To build and test a similar circuit, go to experiment 6 in your lab manual laboratory. To revive your memory, here i bring the ce circuit configuration. Equipment and components used 30 mhz dual channel cathode ray oscilloscope 3 mhz function generator 030 v dc dual regulated power supply 4. Experiment 6 transistors as amplifiers and switches our final topic of the term is an introduction to the transistor as a discrete circuit element. Common emitter configuration commonly used in lownoise amplifiers.
Commonemitter amplifiers give the amplifier an inverted output and can have a very high gain that may vary widely from one transistor to the next. Note that all external capacitors are assumed to be short circuits at. While more detailed bestpractice designs exist, the circuit above is the best for teaching purposes. What are the application of common emitter amplifier.
Experiment 3 common emitter amplifier free download as pdf file. By reading the above information you have got an idea about this concept. Conclusion in this experiment we learned what a common. Ce amplifiers exhibit high voltage gain and high current gain. The ac signal voltage gain is defined as a v v o v i where v o and v i can both be rms, peak, or peakpeak values. The name common source comes from the fact that when the source terminal is grounded, it becomes a common. The reason for this can be seen from the fact that as the input voltage rises, so the current increases through the base circuit. Be prepared to discuss your experiment with your ta.
1298 127 6 346 582 761 549 69 1122 1328 1400 1498 1439 368 284 839 773 653 1041 131 608 1127 776 256 710 1467 631 922 229 718 269 690 127 755 108 391 1455 119 32 819 137 341 1393 60 1271 403 16 136 920