Dr.NNCE ECE/IVSEM LIC LAB-LM

Transcription

1 EC LINEAR INTEGRATED CIRCUITS LABORATORY LABORATORY MANUAL FOR IV SEMESTER B.E (ECE) ACADEMIC YEAR( ) (FOR PRIVATE CIRCULATION ONLY) ANNA UNIVERSITY CHENNAI (REGULATION 2008) DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING DR.NAVALAR NEDUNCHEZHIYAN COLLEGE OF ENGINEERING THOLUDUR , CUDDALORE DISTRICT 1

2 HARDWARE REQUIREMENTS: CRO (30/60 MHz) FUNCTION GENERATOR (1 MHz Range) REGULATED POWER SUPPLY (0-30) DUAL POWER SUPPLY (±15V/± 12V) BREAD BOARD TRANSFORMER & CONSUMABLES ALLOTMENT OF MARKS INTERNAL ASSESMENT PRACTICAL EXAM TOTAL : 20 MARKS : 80 MARKS : 100 MARKS OBSERVATION RECORD NOTE CIA I CIA II MODEL EXAM ATTENDANCE TOTAL INTERNAL ASSESMENT (20 MARKS) SPLIT UP OF INTERNAL MARKS : 3 MARKS : 7 MARKS : 2 MARKS : 2 MARKS : 3 MARKS : 3 MARKS : 20 MARKS UNIVERSITY EXAMINATION The Exam will be conducted for 100 marks. Then the marks will be converted to 80 marks. ALLOCATION OF MARKS Aim and Result : 10 marks Circuit diagram and Tabulation : 20 Marks Connection : 30 Marks Output : 30 Marks Viva Voce : 10 Marks Total : 100 Marks 2

3 GENERAL INSTRUCTIONS FOR LABORATORY CLASSES Enter the Lab with CLOSED FOOTWEAR. Boys should TUCK IN the shirts. Students should wear uniform only. LONG HAIR should be protected, let it not be loose especially near ROTATING MACHINERY. Any other machines / equipments should not be operated other than the prescribed one for that day. POWER SUPPLY to your test table should be obtained only through the LAB TECHNICIAN. Do not LEAN and do not be CLOSE to the rotating components. TOOLS, APPARATUS and GUAGE sets are to be returned before leaving the lab. HEADINGS and DETAILS should be neatly written Aim of the experiment Apparatus / Tools / Instruments required Procedure / Theory / Algorithm / Program Model Calculations Neat Diagram / Flow charts Specifications / Designs Details Tabulations Graph Result / discussions. Before doing the experiment, the student should get the Circuit / Program approval by the FACULTY -IN -CHARGE. Experiment date should be written in the appropriate place. After completing the experiment, the answer to the viva-voce questions should be neatly written in the workbook. Be PATIENT, STEADY, SYSTEMATIC AND REGULAR. 3

4 LIST OF EXPERIMENTS 1. Inverting, Non-inverting and Differential amplifiers. 2. Integrator and Differentiator. 3. Instrumentation amplifier. 4. Active lowpass, Highpass and Bandpass filters. 5. Astable and Monostable multivibrators and Schmitt trigger using Op-Amp. 6. Phase shift and Wien bridge oscillators using Op-Amp. 7. Astable and Monostable multivibrators using NE555 timer. 8. PLL characteristics and its use as frequency multiplier. 9. DC power supply using LM317 and LM Study of SMPS. 11. Simulation of Instrumentation amplifier using PSpice. 12. Simulation of Active lowpass, Highpass and Bandpass filters using PSpice. 13. Simulation of Astable and Monostable multivibrators and Schmitt trigger using PSpice. 14. Simulation of Phase shift and Wien bridge oscillators using PSpice. 15. Simulation of Astable and Monostable multivibrators using PSpice. 4

5 CONTENTS Ex. No Name of the Experiment Page No. 01 Inverting, Non-inverting and Differential amplifiers 02 Integrator and Differentiator 03 Instrumentation amplifier 04 Active lowpass, Highpass and Bandpass filters 05 Astable and Monostable multivibrators and Schmitt trigger using Op-Amp 06 Phase shift and Wien bridge oscillators using Op-Amp 07 Astable and Monostable multivibrators using NE555 timer 08 PLL characteristics and its use as frequency multiplier 09 DC power supply using LM317 and LM Simulation of Instrumentation amplifier using PSpice 11 Simulation of Active lowpass, Highpass and Bandpass filters using PSpice 12 Simulation of Astable and Monostable multivibrators and Schmitt trigger using PSpice 13 Simulation of Phase shift and Wien bridge oscillators using PSpice 14 Simulation of Astable and Monostable multivibrators using PSpice 15 Study of SMPS 5

6 PIN DIAGRAM: CIRCUIT DIAGRAM: INVERTING AMPLIFIER: MODEL GRAPH: 6

7 Exercise/Experiment Number: 1 Title of the exercise/experiment Date of the experiment : INTRODUCTION : Inverting, Non-inverting and Differential amplifiers OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To construct and test the performance of an Inverting, Non-inverting amplifier and Differential amplifier using IC µa 741 ACQUISITION A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 2 Resistors 1KΩ;5 KΩ;100 KΩ Each 2 3 Regulated Power Supply (0-30)V 1 4 IC µa Voltmeter (0-50)V 1 6 Connecting Wires - - B. DESIGN: INVERTING AMPLIFIER: Let A = -5; R1 = 1KΩ A = Rf / R1 Rf = 5 KΩ Rcomp = R1 Rf / R1 + Rf = 833 Ω NON-INVERTING AMPLIFIER: Let A = 6; R1 = 1KΩ A = 1 + (Rf / R1) Rf = 5 KΩ Rcomp = R1 Rf / R1 + Rf = 833 Ω NON-INVERTING AMPLIFIER: Let A = 100; R1 = 1KΩ A = R2 / R1 R2 = 100 KΩ 7

8 CIRCUIT DIAGRAM: NON-INVERTING AMPLIFIER: MODEL GRAPH: DIFFERENTIAL AMPLIFIER: 8

9 C. THEORY: INVERTING AMPLIFIER: The fundamental component of any analog computer is the operational amplifier or op-amp and the frequency configuration in which it is used as an inverting amplifier. An input voltage Vin is applied to the input voltage. It receives and inverts its polarity producing an output voltage. this same output voltage is also applied to a feedback resistor Rf, which is connected to the amplifier input analog with R1. The amplifier itself has a very high voltage gain. If Rf = R1 then Vo=Vi NON- INVERTING AMPLIFIER: Although the standard op-amp configuration is as an inverting amplifier, there are some applications where such inversion is not wanted. However, we cannot just switch the inverting and non inverting inputs to the amplifier itself. We will still need negative feedback to control the working gain of the circuit.therefore, we will need to leave the resistor structure around the op-amp intact and swap the input and ground connections to the overall circuit. VO/VI = (Rf / Ri) +1 From the calculations, we can see that the effective voltage gain of the non-inverting amplifier is set by the resistance ratio. Thus, if the two resistors are equal value, then the gain will be 2 rather than 1. DIFFERENTIAL AMPLIFIER: A circuit that amplifies the difference between two signals is called as a differential amplifier. This type of amplifiers is very useful in instrumentation circuits. From the experimental setup of a differential amplifier, the voltage at the output of the operational amplifier is zero. The inverting and non-inverting terminals are at the same potential. Such a circuit is very useful in detecting very small differences in signals. Since the gain can be chosen to be very large. For example, if R2=100R1, then a small difference V1-V2 is amplified 100 times. 9

10 TABULATION: INVERTING AMPLIFIER: S.No Input Voltage (in volts) Output Voltage (in volts) NON- INVERTING AMPLIFIER: S.No Input Voltage (in volts) Output Voltage (in volts) DIFFERENTIAL AMPLIFIER: S.No Input Voltage (in volts) Output Voltage (in volts) V1 V

11 D. PROCEDURE: Connections are made as per the EXPERIMENTAL SETUP. The supply is switched ON. Output is connected to anyone channel of CRO. The V1 and V2 voltages are fixed and measured from the other channel of CRO and the corresponding output voltages are also noted from the CRO. The above step is repeated for various values of V1 and V2.V1 and V2 may be AC or DC voltages from function generator or DC power supply. Readings are tabulated and gain was calculated and composed with designed values. REVIEW QUESTIONS: 1. Define an operational amplifier. An operational amplifier is a direct-coupled, high gain amplifier consisting of one or more differential amplifier. By properly selecting the external components, it can be used to perform a variety of mathematical operations. 2. Mention the characteristics of an ideal op-amp. * Open loop voltage gain is infinity. *Input impedance is infinity. *Output impedance is zero. *Bandwidth is infinity. *Zero offset. 3. Define input offset voltage. A small voltage applied to the input terminals to make the output voltage as zero when the two input terminals are grounded is called input offset voltage. 4. Define input offset current. The difference between the bias currents at the input terminals of the op-amp is called as input offset current. RESULT Thus the Inverting, Non-inverting and Differential amplifier using op-amp was designed and tested. 11

12 CIRCUIT DIAGRAM: DIFFERENTIATOR: MODEL GRAPH: 12

13 Exercise/Experiment Number: 2 Title of the exercise/experiment Date of the experiment : INTRODUCTION 741 ACQUISITION : Integrator and Differentiator OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To construct and test the performance of an Integrator and Differentiator using IC µa A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 2 Resistors 31.8KΩ;3.1KΩ;10KΩ;100KΩ; Each 1. 1KΩ 3 3 Regulated Power Supply (0-30)V 1 4 IC µa AFO (0-1)MHz 1 6 Capacitor 0.1μF 1 7. CRO (0-20)MHz 1 8. Connecting Wires - - B. DESIGN: DIFFERENTIATOR: Let fa = 50 Hz; C1 = 0.1μF fa = 1 / 6.28 Rf C1 Rf = 31.8KΩ Rf = 10R1 R1 = 3.1 KΩ INTEGRATOR: Let fb = 50 Hz; Cf = 0.1μF fb = 1 / 6.28 R1 Cf R1 = 10KΩ Rf = 10R1 Rf = 100 KΩ 13

14 INTEGRATOR: MODEL GRAPH: 14

15 C. THEORY: DIFFERENTIATOR: Op-amps allow us to make nearly perfect integrators such as the practical integrator the circuit incorporates a large resistor in parallel with the feedback capacitor. This is necessary because real op-amps have a small current flowing at their input terminals called the "bias current". This current is typically a few nanoamps, and is neglected in many circuits where the currents of interest are in the microamp to milliamp range. The feedback resistor gives a path for the bias current to flow. The effect of the resistor on the response is negligible at all but the lowest frequencies. INTEGRATOR: One of the simplest of the operational amplifier that contains capacitor is differential amplifier.as the suggests, the circuit performs the mathematical operation of differentiation.the output is the derivative of the given input signal voltage.the minus sign indicates a phase shift of the output waveform Vo with respect to the input signal. 15

16 TABULATION: Amplitude (Volts) Time Period (ms) Input Differentiator Output 20 1 Integrator Output

17 D. PROCEDURE: The connections are given as per the experimental setup. The supply is switched ON after checking the circuit connections. The input wave form is applied from the function generator and the corresponding output waveform is noted from the CRO. The above mentioned procedure is repeated for differentiator also. REVIEW QUESTIONS: 1. What are the applications of current sources? Transistor current sources are widely used in analog ICs both as biasing elements and as load devices for amplifier stages. 2. Justify the reasons for using current sources in integrated circuits. *superior insensitivity of circuit performance to power supply variations and temperature. *more economical than resistors in terms of die area required to provide bias currents of small value. *When used as load element, the high incremental resistance of current source results in high voltage gains at low supply voltages. 3. What is the advantage of wilder current source over constant current source? Using constant current source output current of small magnitude (micro amp range) is not attainable due to the limitations in chip area. Wilder current source is useful for obtaining small output currents. Sensitivity of wilder current source is less compared to constant current source. 4.Mention the advantages of Wilson current source. *provides high output resistance. *offers low sensitivity to transistor base currents. RESULT Thus the Integrator and Differentiator using op-amp was designed and tested. 17

18 CIRCUIT DIAGRAM: INSTRUMENTATION AMPLIFIER MODEL GRAPH: 18

19 Exercise/Experiment Number: 3 Title of the exercise/experiment : Instrumentation amplifier Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To design and verify the operation of instrumentation amplifier using IC µa 741 ACQUISITION A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 10KΩ; 5 2 Resistors 100KΩ; 2 120KΩ; 2 3 Regulated Power Supply (0-30)V 1 4 IC µa AFO (0-1)MHz 1 6. CRO (0-20)MHz 1 B 7. Connecting Wires - - B. DESIGN: V01 = (1+R2/R1) V1 (R2/R1) V2, V02 = (1+R2/R1) V2 (R2/R1) V1 V0 = V02 V01 = (V2 V1) (1+2R2/R1), Gain = V0/Vi = Vo / (V2 V1) = (1+2R2/R1) C. THEORY: In a number of instrumentation and consumer applications one is required to measure and control the physical quantities. Some typical examples are measurement and control of temperature, humidity, light, Intensity, water flow etc. These physical quantities are usually measured with the help of transducer. The output of the transducer has to be amplified so that it can derive the indicator or display system. The functions performed by an instrumentation amplifier are, High gain accuracy. 19

20 TABULATION: S.NO. V1 (V) V2 (V) Vd = V2~V1 Vo (V) GAIN

21 High CMRR. High gain stability with low temperature coefficient. Low dc offset. Low input impedance. These are specially designed op-amp such as VA725 to meet the above started requirement of a good instrumentation amplifier. Monolithic instrumentation amplifiers are also available commercially such as AD521, AD524, and AD624 by analog devices L40036, and L40037 by national semiconductors. D. PROCEDURE: Circuit connections are given as per the experimental setup. The input signal is given. The dual power supply is switched ON. The input is varied in steps and the corresponding output readings are noted from CRO. The practical gain is calculated from the readings. REVIEW QUESTIONS: 1. What is the need for an instrumentation amplifier? In a number of industrial and consumer applications, the measurement of physical quantities is usually done with the help of transducers. 2. Mention some of the linear applications of op amps. Adder, subtractor, voltage to current converter, current to voltage converters, instrumentation amplifier, analog computation, power amplifier, etc are some of the linear op-amp circuits. 3. Mention some of the non linear applications of op-amps. Rectifier, peak detector, clipper, clamper, sample and hold circuit, log amplifier, anti log amplifier, multiplier are some of the non linear op-amp circuits. 4. What are the areas of application of non-linear op- amp circuits? Industrial instrumentation, Communication and Signal processing RESULT Thus the instrumentation amplifier is designed and tested using IC µa

22 CIRCUIT DIAGRAM: ACTIVE LOW PASS FILTER: MODEL GRAPH: 22

23 Exercise/Experiment Number: 4 Title of the exercise/experiment Date of the experiment : INTRODUCTION : Active low pass, High pass and Band pass filters. OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT filters using IC µa 741 ACQUISITION To design and verify the operation of the Active low pass, High pass and Band pass A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 2 Resistors 3 Capacitor 0.1μF;0.01μF 2 4 IC µa AFO (0-1)MHz 1 6. CRO (0-20)MHz 1 7. B Connecting Wires - - B. DESIGN: LOW PASS & HIGH PASS: fh = 1 / 6.28 RC For LPF fh = 1 KHz and HPF fl = 1 KHz; Assume C = 0.1Μf R = 1.6KΩ A = 3 α; where α = damping = Rf = 5.8 KΩ BAND PASS: A = 1 + Rf / R1; Let R1 = 10KΩ fc = 1KHz; AF = 10 & Q = 3 Let C1 = C2 = 0.01μF R1 = Q / 6.28 fc C AF = 4.77KΩ R2 = Q / 6.28 fc C (2Q 2 AF) = 5.97 KΩ R3 = Q / 3.14 fc C = 95.5 KΩ KΩ;1.2KΩ;10KΩ;6.2KΩ;100KΩ 1.5KΩ; 100Ω; 1 2

24 ACTIVE HIGH PASS FILTER: MODEL GRAPH: 24

25 C. THEORY: The first order low pass filter is realized RC circuit used along with an op-amp in non-inverting configuration. A low pass filter has constant gain from) Hz to fh.. Bandwidth of this filter is fh. Bandwidths of electric filters are used in circuits which require the separation of signals according to their frequencies. a first order low pass filter consists of a single RC network connected to the positive input terminal of non-inverting op-amp amplifier. Resistors Ri and Rf determine the gain of the filter in the pass band. The parameters in the band pass filter are lower cutoff frequency, the upper cutoff frequency and the bandwidth, the central frequency gain Ao and selectivity Q. The higher selectivity Q, the sharper the filter. Below 0.5fo all filters roll off at -20dB/decade independent of the value of Q. This is limited by the two RC pair of circuits. D. PROCEDURE: Connections are given as per the experimental setup. Supply is switched ON after checking the connections. Input voltage is set to 1V and by changing the input frequency, output voltage is measured. The procedure is applied to active low pass; high pass and band pass filters 25

26 CIRCUIT DIAGRAM: BAND PASS FILTER: MODEL GRAPH: 26

27 27

28 TABULATION: LOW PASS FILTER: InputVoltage Vi = 0.5 Frequency Output Voltage Gain = 20log(Vo / Vi) K 2K 3K 4K 6K 10K HIGH PASS FILTER: InputVoltage Vi = 0.5 Frequency Output Voltage Gain = 20log(Vo / Vi) K 2K 3K 4K 5K 6K BAND PASS FILTER: InputVoltage Vi = 0.5 Frequency Output Voltage Gain = 20log(Vo / Vi) K 2K 9K 10K 20K 60K

29 REVIEW QUESTIONS: 1. Define sensitivity. Sensitivity is defined as the percentage or fractional change in output current per percentage or fractional change in power-supply voltage. 2. What do you mean by a precision diode? The major limitation of ordinary diode is that it cannot rectify voltages below the cut in voltage of the diode. A circuit designed by placing a diode in the feedback loop of an op amp is called the precision diode and it is capable of rectifying input signals of the order of mill volt. 3. Write down the applications of precision diode. Half - wave rectifier Full - Wave rectifier Peak value detector Clipper Clamper 4. List the applications of Log amplifiers Analog computation may require functions such as lnx, log x, sin hx etc. These functions can be performed by log amplifiers Log amplifier can perform direct db display on digital voltmeter and spectrum analyzer Log amplifier can be used to compress the dynamic range of a signal RESULT Thus the operation of Active Low Pass Filter, High Pass Filter and Band Pass Filter was designed and output was tested using IC µa

30 CIRCUIT DIAGRAM: ASTABLE MULTIVIBRATORS: MODEL GRAPH: 30

31 Exercise/Experiment Number: 5 Title of the exercise/experiment : Astable, Monostable multivibrators and Schmitt Date of the experiment : INTRODUCTION trigger using Op-Amp. OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To design and construct an Astable, Monostable multivibrators and Schmitt trigger using IC µa 741 ACQUISITION A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 B 2 Resistors 4.5KΩ;1KΩ;27KΩ;22KΩ;5.6KΩ;760Ω 1.5KΩ; 10KΩ; 3 Capacitor 0.1μF;0.01μF 1 4 IC µa AFO (0-1)MHz 1 6. CRO (0-20)MHz 1 7. Diode 0A Connecting Wires B. DESIGN: ASTABLE MULTIVIBRATORS: Feedback factor = R2 / (R1 + R2) T = 2RC ln[(1 + β)/(1 β)] Let R1 = R2 = 10KΩ then β = 0.5 Assume C = 0.1μF; for a time period of 1ms T = 2RC ln 3 Rf = 4.55KΩ SCHMITT TRIGGER: Vut = (R2 / R1 + R2) Vsat ; Vlt = (R2 / R1 + R2) Vsat Let Vut = 0.5V; Vlt = 0.5 R1 = 27 R2 ; Let R1 = 1KΩ; R2 = 27KΩ 31

32 CIRCUIT DIAGRAM: MONOSTABLE MULTIVIBRATORS: MODEL GRAPH: 32

33 C. THEORY: ASTABLE MULTIVIBRATOR: The astable multivibrator is also known as free running oscillator. the principle of generation of square wave output is to force an op-amp to operate in saturation region. β = R2/ (R1+R2) of the output is feedback to the positive input terminal. the reference voltage is Vo and may take the values as +βvsat and βvsat. The output is also feedback to the negative input terminal after interchanging by a low pass RC combination. Whenever input terminal just exceeds Vref switching takes place resulting in square wave output. In this multivibrator both sates are quasi stable state MONOSTABLE MULTIVIBRATOR: The monostable multivibrator is also called as one shot multivibrator. The circuit produces a single pulse of specified duration in response to each external trigger response. it is always have one stable state. When an external trigger is applied, the output changes the state. The new state is called quasi stable state. The circuit remains in this state for a fixed interval of time and then it returns to the original state after this interval. This time interval is determined by the charging and discharging of the capacitor. SCHMITT TRIGGER: If the positive feedback is added to the comparator circuit means gain can be increased greatly. Consequently the transfer curve comparator becomes more close to the ideal curve theoretically. If the loop gain βfo is adjusted to unity then the gain with feedback average becomes extreme values of output voltage. in practical circuits, however it may not be possible to maintain loop gain exactly equal to unity for a long time because of supply voltage and temperature variations so a value greater than unity is chosen. This gives the output waveform virtually disconnected at the comparison voltage. This circuit however exhibits phenomenon called hystersis or backlash. 33

34 CIRCUIT DIAGRAM: SCHMITT TRIGGER: MODEL GRAPH: 34

35 D. PROCEDURE: ASTABLE MULTIVIBRATOR: Connections are given as per the experimental setup. Supply is switched ON after checking the circuit connections. The output square wave form and the capacitor charging and discharging waveforms are noted from the CRO. MONOSTABLE MULTIVIBRATOR: Connections are given as per the experimental setup. Supply is switched ON after checking the circuit connections. The output square wave form and the capacitor charging and discharging waveforms are note down from the CRO. SCHMITT TRIGGER: Connections are given as per the experimental setup. The supply is switched ON. The output waveform was noted from CRO and UTP and LTP are noted. The graph is drawn. 35

36 TABULATION: ASTABLE MULTIVIBRATOR: Amplitude (V) Time Period (ms) Input TON = 0.5 Output 11.5 TOFF = 0.5 MONOSTABLE MULTIVIBRATOR: Amplitude (V) Time Period (ms) Input TON = 0.5 Output 11 TOFF = 1 SCHMITT TRIGGER: Amplitude (V) Time Period (ms) Input 6 1 TON = 0.5 Output 11 TOFF =

37 REVIEW QUESTIONS: 1. What are the applications of comparator? Zero crossing detectors Window detector Time marker generator Phase detector 2. What is a Schmitt trigger? Schmitt trigger is a regenerative comparator. It converts sinusoidal input into a square wave output. The output of Schmitt trigger swings between upper and lower threshold voltages, which are the reference voltages of the input waveform. 3. What is a multivibrator? Multivibrators are a group of regenerative circuits that are used extensively in timing applications. It is a wave shaping circuit which gives symmetric or asymmetric square output. It has two states stable or quasi- stable depending on the type of multivibrator. 4. What do you mean by monostable multivibrator? Monostable multivibrator is one which generates a single pulse of specified duration in response to each external trigger signal. It has only one stable state. Application of a trigger causes a change to the quasi-stable state. An external trigger signal generated due to charging and discharging of the capacitor produces the transition to the original stable state. RESULT Thus the operation of Astable, Monostable multivibrators and Schmitt trigger was designed and output was tested using IC µa

38 CIRCUIT DIAGRAM: RC PHASE SHIFT OSCILLATOR: MODEL GRAPH: 38

39 Exercise/Experiment Number: 6 Title of the exercise/experiment Date of the experiment : INTRODUCTION : RC Phase shift and Wien bridge oscillators OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To design and test RC phase shift and Wien bridge oscillators using IC µa 741. ACQUISITION A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 B 2 Resistors B. DESIGN: RC PHAASE SHIFT OSCILLATOR: Given, fo = 500Hz; Assume C = 0.1µF fo = 1/(2π 6 RC), R = 1.3KΩ R1 = 10R = 13KΩ Av= Rf / R1, Av > -29, ie, Rf/ R1 > 29 Rf = 390KΩ Rcomp = (R1Rf / R1 + Rf) = 15KΩ WIEN BRIDGE OSCILLATOR: Given, fo = 10KHz; Assume C = 0.01µF fo = 1/(2π 6 RC), R = 1.59KΩ R1 = 10R = 15.9KΩ Rf = 2R1 = 31.8KΩ 39 13KΩ;15KΩ;390KΩ;31.8KΩ;15.9KΩ; 1.5KΩ; 1.59KΩ 3 Capacitor 0.1μF; μF 2 4 IC µa AFO (0-1)MHz 1 6. CRO (0-20)MHz 1 7. Connecting Wires

40 CIRCUIT DIAGRAM: WEIN BRIDGE OSCILLATOR: MODEL GRAPH: 40

41 C.THEORY: RC PHAASE SHIFT OSCILLATOR: RC phase shift oscillator using op-amp, in inverting amplifier mode. Thus it introduces a phase shift of between the input and output. The feedback network consists of 3 RC sections producing each 60 0 phase shift. Such a circuit is known as RC phase shift network. The circuit is generating its own output signal and a stage of oscillator sustained. The phase shift produced by op-amp is the op-amp with a gain of 29 and RC network is of equal resistor and capacitor connected feedback the op-amp output and input terminals. Resistor and junctions as a last resistor in phase shift network, give here is a phase load network produces an shift so that total loop phase shift is WIEN BRIDGE OSCILLATOR: It is commonly used in audio frequency oscillator. The feedback signal is connected in the input terminal so that the output amplifier is working as a non-inverting amplifier. The Wien bridge circuit is connected between amplifier input terminal and output terminal. The bridge has a series R network, in one arm and a parallel RC network in the adjoining arm. In the remaining two arms of the bridge, resistor R1 and Rf are connected. the phase angle criterion for oscillation is that the total phase shift around the circuit must be zero. This condition occurs when bridge is balanced. At resonance frequency of oscillation is exactly the resonance frequency of balanced Wien bridge and is given by f0 = 1/ (2πfC).assuming that the resistors are input impedance value and capacitance are equal to the value in the reactive stage of Wien bridge. At this frequency, the gain required for sustained. D.PROCEDURE: RC PHAASE SHIFT OSCILLATOR: Circuit connections are given as per the experimental setup. Supply is switched ON phase shift output is obtained at the output. The inverting op-amp produce and RC network produce another Frequency is calculated by the formula f =1/T 41

42 TABULATION: RC PHAASE SHIFT OSCILLATOR: Amplitude (V) Time Period (ms) WIEN BRIDGE OSCILLATOR: Amplitude (V) Time Period (ms)

43 WIEN BRIDGE OSCILLATOR: Connections are given as per the experimental setup. Resistor and capacitor values are verified simultaneously; the corresponding Rf value is noted. The critical vale of frequency is noted correspondingly. Check whether the calculated and observed frequency values are same. Graph is drawn by taking amplitude along y-axis and time along x- axis.the graph will be sine waveform. REVIEW QUESTIONS: 1. Define conversion time. It is defined as the total time required converting an analog signal into its digital output. It depends on the conversion technique used & the propagation delay of circuit components. 2. What is settling time? It represents the time it takes for the output to settle within a specified band ±½LSB of its final value following a code change at the input (usually a full scale change). It depends upon the switching time of the logic circuitry due to internal parasitic capacitance & inductances. Settling time ranges from 100ns.10µs depending on word length & type circuit used. 3. Explain in brief stability of a converter. The performance of converter changes with temperature age & power supply variation. So all the relevant parameters such as offset, gain, linearity error & monotonicity must be specified over the full temperature & power supply ranges to have better stability performances. 4. What are the problems associated with switch type phase detector? The output voltage Ve is proportional to the input signal amplitude. This is undesirable because it makes phase detector gain and loop gain dependent on the input signal amplitude. RESULT Thus the operation of RC phase shift and Wien bridge oscillators was designed and output was tested using IC µa

44 PIN DIAGRAM: CIRCUIT DIAGRAM: ASTABLE MULTIVIBRATORS: MODEL GRAPH: 44

45 Exercise/Experiment Number: 7 Title of the exercise/experiment : Astable and Monostable multivibrators using NE555 Timer. Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To design and construct an Astable and Monostable multivibrators using NE555 Timer. ACQUISITION A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 B 2 Resistors 3.625KΩ;7.25KΩ; 10KΩ; 3 Capacitor 0.1μF;0.01μF;0.001µF 1 4 IC AFO (0-1)MHz 1 6. CRO (0-20)MHz 1 7. Diode 0A Connecting Wires B. DESIGN: ASTABLE MULTIVIBRATORS: CASE1: Given f = 1 KHz and D = 0.5 f = 1.45 / (RA + RB) C; D = RB / (RA + RB) = 0.5 RA = RB; Let C = 0.1µF; RA = RB = R f = 1.45 /2RC; R = 7.2KΩ CASE2: f = 1.45 / (RA + 2RB) C;D = RB / (RA + 2RB) = 0.25 RA = 2RB ; Let C = 0.1µF; RA = 2RB = 4RB f = 1.45 / 4RBC; RB = 3.625KΩ; RA =7.25KΩ MONOSTABLE MULTIVIBRATORS: Time Period of monostable multivibrator = 1.1RC T = 1m/s; Assume C= 0.1µF R = T / 1.1C R = 10KΩ 45

46 CIRCUIT DIAGRAM: MONOSTABLE MULTIVIBRATORS: MODEL GRAPH: 46

47 C. THEORY: ASTABLE MULTIVIBRATOR: The astable multivibrator is also called the free running multivibrator. It has two quasi states i.e. no stable states as such the circuit conditions oscillate between the components values used to decide the time for which circuit remains in each stable state. the principle of square wave output is to force the IC to operate in saturation region. Whenever input at the negative input terminal just exceeds Vref switching takes place resulting in a square wave output. In astable multivibrator both stable states and one quasi state are present. MONOSTABLE MULTIVIBRATOR: These multivibrators are comprised of group of regenerative circuits that are commonly used in timing applications. The circuit produces a single pulse of applied duration in response to each external trigger pulse. For each circuit only one state exists. When an external trigger is applied the output changes its state. The new state is called quasi-stable state. D. PROCEDURE: ASTABLE MULTIVIBRATOR: Connections are given as per the experimental setup. Supply is switched ON after checking the circuit connections. The output square wave form and the capacitor charging and discharging waveforms are noted from the CRO. MONOSTABLE MULTIVIBRATOR: Connections are given as per the experimental setup. Supply is switched ON after checking the circuit connections. The output square wave form and the capacitor charging and discharging waveforms are note down from the CRO. 47

48 TABULATION: ASTABLE MULTIVIBRATOR: Amplitude (V) Time Period (ms) Input TON = 0.5 Output 11.5 TOFF = 0.5 MONOSTABLE MULTIVIBRATOR: Amplitude (V) Time Period (ms) Input TON = 0.5 Output 11 TOFF = 1 48

49 REVIEW QUESTIONS: 1. What are the applications of comparator? Zero crossing detectors Window detector Time marker generator Phase detector 2. What is a Schmitt trigger? Schmitt trigger is a regenerative comparator. It converts sinusoidal input into a square wave output. The output of Schmitt trigger swings between upper and lower threshold voltages, which are the reference voltages of the input waveform. 3. What is a multivibrator? Multivibrators are a group of regenerative circuits that are used extensively in timing applications. It is a wave shaping circuit which gives symmetric or asymmetric square output. It has two states stable or quasi- stable depending on the type of multivibrator. 4. What do you mean by monostable multivibrator? Monostable multivibrator is one which generates a single pulse of specified duration in response to each external trigger signal. It has only one stable state. Application of a trigger causes a change to the quasi-stable state. An external trigger signal generated due to charging and discharging of the capacitor produces the transition to the original stable state. RESULT Thus the operation of Astable and Monostable multivibrators was designed and output was tested using NE555 Timer. 49

50 BLOCK DIAGRAM OF NE565 PLL: CIRCUIT DIAGRAM: 50

51 Exercise/Experiment Number: 8 Title of the exercise/experiment : PLL Characteristics and Frequency multiplier. Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To design and construct a PLL Characteristics and Frequency multiplier using NE 565. ACQUISITION A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 B 2 Resistors 6.8KΩ;20KΩ;2KΩ;10KΩ; 4.7KΩ; 3 Capacitor 1μF;10μF;0.01μF;0.001µF 1 4 IC NE AFO (0-1)MHz 1 6. CRO (0-20)MHz 1 7. Transistor 2N Connecting Wires B. THEORY: The block diagram of LM565 PLL consists of base detector amplifier. low pass filter and VCO as shown in the block diagram. The phase locked loop is not connected internally. It is necessary to connect output of VCO (pin 4) to phase comparator in pin 5 externally. in frequency multiplication applications a digital frequency driver is inserted into loop between pin 4 and pin 5.the centre frequency of PLL is determined by free running frequency multiplier of VCO given by free funning frequency of VCO which is given by f0 = 1.2 / (4R1C1) Hz. the value of Ri is restricted from 2KΩ to 20KΩ but a capacitor can have any value. A capacitor C2 is connected between pin 7 and to the Positive supply from a first order low pass filter with an external resistance of 3.6 KΩ. 51

52 CIRCUIT DIAGRAM: PLL AS FREQUENCY MULTIPLIER: 52

53 The value of filter capacitor C2 should be large enough to eliminate positive oscillator into VCO voltage. FL = I.8fo/V Hz. Where, fo = free running frequency in Hz V = +V ( V) volts FL = ± (fo /2π3.6x10 3 C2) 1/2 Where, C2 is in farads D. PROCEDURE: Connections are given as per the experimental setup. Observe the waveform at pin 4 and pin 5 without any input signal. This is free running frequency of VCO (fo). Switch ON the functional generator and give the square waveform of 1Vpp & 1KHz. Gradually increase the fi till the PLL is locked with fi 100Hz to 4KHz and note down the FL2 and FL1 then decrease the frequency from 4KHz to 1000Hz and note down the f3 and f1. Calculate the capture range and lock range. 53

54 TABULATION: Amplitude Time Period Input Output 54

55 REVIEW QUESTIONS: 1. Mention some areas where PLL is widely used. *Radar synchronisation *satellite communication systems *air borne navigational systems *FM communication systems *Computers. 2. List the basic building blocks of PLL *Phase detector/comparator *Low pass filter *Error amplifier *Voltage controlled oscillator 3. What are the three stages through which PLL operates? *Free running *Capture *Locked/ tracking 4. Define lock-in range of a PLL. The range of frequencies over which the PLL can maintain lock with the incoming signal is called the lock-in range or tracking range. It is expressed as a percentage of the VCO free running frequency. RESULT Thus the operation of PLL Characteristics and Frequency multiplier was designed and output was tested using NE565 Timer. 55

56 CIRCUIT DIAGRAM: LM 723 VOLTAGE REGULATORS: MODEL GRAPH: 56

57 Exercise/Experiment Number: 9 Title of the exercise/experiment : DC Power Supply using LM317 and LM723. Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To design and construct a DC Power Supply using LM317 and LM723. ACQUISITION A. APPARATUS REQUIRED: S. No. Name Range Quantity 1 Dual Power Supply (0-30)V 1 B 2 Resistors 620Ω;2.2KΩ;10KΩ;33KΩ; 3.3KΩ;240Ω 3 Capacitor 1μF;10μF;0.001µF 1 4 LM317 & LM Ammeter (0-50)mA 1 6. Voltmeter (0-20)V 1 7. Decade Resistor Box Connecting Wires B. DESIGN: Designing an adjustable voltage regulator LM317 to satisfy the following specifications: Output Voltage Vo = 5 to 12V Output Current Io = 1A IAdj = 100 µa maximum. If we use R1 = 240Ω; then for Vo = 5V Vo = VREF (1 + R2 / R1) + IAdjR2 R2 = 3.75 / (5.3) (10-4 ) = 0.71KΩ Similarly for Vo = 12V, 12 = 1.25 (1 + R2 / 240) + (10-4 ) R2 R2 = / (5.3) (10-3 ) = 2.01KΩ 57

58 LM317 VOLTAGE REGULATOR: 58

59 C. THEORY: The basic voltage regulator in its simplest form consists of a) Voltage reference Vr b) Error amplifier c) Feedback network d) Active series or shunt control unit. The voltage reference generates a voltage level which is applied to the comparator circuit, which is generally error amplifier. The second input to the error amplifier obtained through feedback network. Generally using the potential divider, the feedback signal is derived by sampling the output voltage. The error amplifier converts the difference between the output sample and the reference voltage into an error signal. This error signal in turn controls the active element of the regulator circuit, in order to compensate the changes in the output voltage. Such an active element is generally a transistor. Error amplifier controls the series pass transistor Q2 which acts as a variable resistor. The series pass transistor is small power transistor having about 800mW power dissipation. The unregulated power supply source of (< 36 V d.c) is connected to collector of series pass transistor. Transistor Q2 acts as current limiter in case of short circuit condition. It senses drop across Rsc placed in series with regulated output voltage externally. The frequency compensation terminal controls the frequency response of the error amplifier. The required roll-off is obtained by connecting a small capacitor of 100pF between frequency compensation and inverting input terminals. D. PROCEDURE: Connections are given as per the experimental setup. The input voltage is given to the circuit and the output voltage slowly varies from zero. Then the output voltage attains the designed value and then it is irrespective of input voltage (the output becomes constant). 59

60 TABULATION: Resistance (Ω) Current (ma) Voltage (Volt) K 2K 3K 4K 5K

61 REVIEW QUESTIONS: 1. What is settling time? It represents the time it takes for the output to settle within a specified band ±½LSB of its final value following a code change at the input (usually a full scale change). It depends upon the switching time of the logic circuitry due to internal parasitic capacitance & inductances. Settling time ranges from 100ns.10µs depending on word length & type circuit used. 2. Explain in brief stability of a converter: The performance of converter changes with temperature age & power supply variation. So all the relevant parameters such as offset, gain, linearity error & monotonicity must be specified over the full temperature & power supply ranges to have better stability performances. 3. What is meant by linearity? The linearity of an ADC/DAC is an important measure of its accuracy & tells us how close the converter output is to its ideal transfer characteristics. The linearity error is usually expressed as a fraction of LSB increment or percentage of full-scale voltage. A good converter exhibits a linearity error of less than ±½LSB. 4. What is monotonic DAC? A monotonic DAC is one whose analog output increases for an increase in digital input. RESULT Thus the operation of DC Power Supply was designed and output was tested using LM317 and LM

62 SCHEMATIC DIAGRAM: INSTRUMENTATION AMPLIFIER WAVEFORM: 62

63 Exercise/Experiment Number: 10 Title of the exercise/experiment : Instrumentation amplifier Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To simulate instrumentation amplifier circuit using PSPICE circuit simulator and to verify the corresponding graphs plotted. ACQUISITION A. SOFTWARE REQUIRED: PSPICE student s version 9.1 B. PROCEDURE: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option DC sweep. Choose voltage source and complete the remaining options like start value and end value. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform will pop up after the simulation is done. RESULT Thus the instrumentation amplifier circuit is simulated and the required graphs are plotted. 63

64 SCHEMATIC DIAGRAM: ACTIVE LOW PASS FILTER: WAVE FORM: 64

65 Exercise/Experiment Number: 11 Title of the exercise/experiment : Active low pass, High pass and Band pass filters. Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To simulate Active low pass, High pass and Band pass filters using PSPICE circuit simulator and to verify the corresponding graphs plotted. ACQUISITION A. SOFTWARE REQUIRED: PSPICE student s version 9.1 B. PROCEDURE: ACTIVE LOW PASS FILTER: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option AC sweep. Choose Decade for graph type and complete the remaining options like start value and end value. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform will pop up after the simulation is done. 65

66 SCHEMATIC DIAGRAM: ACTIVE HIGH PASS FILTER: WAVE FORM: 66

67 ACTIVE HIGH PASS FILTER: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option AC sweep. Choose Decade for graph type and complete the remaining options like start value and end value. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform will pop up after the simulation is done. ACTIVE BAND PASS FILTER: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option AC sweep. Choose Decade for graph type and complete the remaining options like start value and end value. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform will pop up after the simulation is done. 67

68 SCHEMATIC DIAGRAM: BAND PASS FILTER: MODEL GRAPH: 68

69 RESULT are plotted. Thus the Active low pass, High pass and Band pass filters is simulated and the required graphs 69

70 SCHEMATIC DIAGRAM: ASTABLE MULTIVIBRATORS: WAVE FORM: 70

71 Exercise/Experiment Number: 12 Title of the exercise/experiment : Astable, Monostable multivibrators and Schmitt trigger using Op-Amp. Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To simulate Astable, Monostable multivibrators and Schmitt trigger using PSPICE circuit simulator and to verify the corresponding graphs plotted. ACQUISITION A. SOFTWARE REQUIRED: PSPICE student s version 9.1 B. PROCEDURE: ASTABLE MULTIVIBRATORS: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option transient. Choose appropriate print step and final time. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform window will pop up after the simulation is done. 71

72 CIRCUIT DIAGRAM: MONOSTABLE MULTIVIBRATORS: MODEL GRAPH: 72

73 MONOSTABLE MULTIVIBRATORS: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option transient. Choose appropriate print step and final time. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform window will pop up after the simulation is done. SCHMITT TRIGGER: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option transient. Choose appropriate print step and final time. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform window will pop up after the simulation is done. 73

74 SCHEMATIC DIAGRAM: SCHMITT TRIGGER: WAVE FORM: 74

75 RESULT Thus the Astable, Monostable multivibrators and Schmitt trigger is simulated and the required graphs are plotted. 75

76 SCHEMATIC DIAGRAM: RC PHASE SHIFT OSCILLATOR: WAVE FORM: 76

77 Exercise/Experiment Number: 13 Title of the exercise/experiment : RC Phase shift and Wien bridge oscillators Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To simulate RC Phase shift and Wien bridge oscillators using PSPICE circuit simulator and to verify the corresponding graphs plotted. ACQUISITION A. SOFTWARE REQUIRED: PSPICE student s version 9.1 B. PROCEDURE: RC PHASE SHIFT OSCILLATOR: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option transient. Choose appropriate print step and final time. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform window will pop up after the simulation is done. 77

78 SCHEMATIC DIAGRAM: WEIN BRIDGE OSCILLATOR: WAVE FORM: 78

79 WEIN BRIDGE OSCILLATOR: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option transient. Choose appropriate print step and final time. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform window will pop up after the simulation is done. RESULT plotted. Thus the RC Phase shift and Wien bridge oscillators is simulated and the required graphs are 79

80 SCHEMATIC DIAGRAM: ASTABLE MULTIVIBRATOR: WAVE FORM: 80

81 Exercise/Experiment Number: 14 Title of the exercise/experiment : Astable multivibrator using NE555 Timer. Date of the experiment : INTRODUCTION OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT To simulate Astable multivibrator using PSPICE circuit simulator and to verify the corresponding graphs plotted. ACQUISITION A. SOFTWARE REQUIRED: PSPICE student s version 9.1 B. PROCEDURE: ASTABLE MULTIVIBRATORS: Draw the schematic diagram in pspice schematic editor. Go choose the icon set up analysis, for choosing proper analysis options. Now select the option transient. Choose appropriate print step and final time. Now choose the icon set up Examine netlist, and if the netlist has no errors, choose the simulate option which is under setup. The waveform window will pop up after the simulation is done. RESULT Thus the Astable multivibrator is simulated and the required graphs are plotted. 81