1Chapter Goals-9• Understand behavior and characteristics of ideal operational amplifiers (op amps)• Study non-ideal op-amp behavior• Demonstrate circuit analysis techniques for ideal and non-ideal op amps• Characterize inverting, non-inverting, summing and instrumentation amplifiers, voltage follower and integrator• Learns factors involved in circuit design using op ampsThe current in the resistor R1 is (by superposition rule)Substituting above equationsClearly the input impedance is very high (why?) and the gain Value can be varied by varying the R1.2i1i1i1=VI/R1, this current also flow through the capacitor, causing charge to accumulate on VC.At time t, the charge Q at the capacitance equal to dttit)(01∫Because i=Q/t and the voltage acrossthe capacitor is dttict)(101∫Because Q=CV. If initial voltage (t=0) on C is denoted VCdtticVtVtCC)(1)(01∫+=Now the output voltage VO=-VC(t)dttiCVVtCO)(101∫−−=dttVCRVVtICO)(10∫−−=In terms of the voltageThus the circuit provides an output voltage that is proportional to timeintegral of the input.We know the current I is the rate of change of chargeiii=dQ/dt, also Q=CVdtdvCvCdtdiII 11)( ==Since A is a virtual groundAdRdtdvCiRvIO)(.22−=−=dttdvCRvIO)(12−=Chapter FifteenApplications and Design of Integrated Circuits3Passive and active filters• Filters are building blocks of communication and instrumentations.• The oldest technology based on inductors and capacitors are called passive LC filters, which are incompatible with any of the modern techniques for assembling electronic systems.• Active-RC filters utilize op amp together with resistors and capacitors.• At present, the most viable approach for realizing fully integrated monolithic filters is the switch capacitance techniques.Active filters Uses of the filters• Some of the uses are listed below:• in electronic power supply ripple smoothing• as tuned circuits in RF stages• for selection of particular sideband as in SSB transmitters• for harmonic frequency suppression in transmitters• As wave trap for eliminating undesirable signal from radio and TV receivers• for improving high and low frequency response in video amplifier• for restricting audio frequency band pass in SSB transmitters• For eliminating undesirable frequency from motors, generators and other electrical and electronic equipment.4One pole active filters• Usually, passive filters suffers from loading effects, substantially reducing the maximum gain from the unity.• Loading effect can be reduced by using active
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