Electronic Devices and Amplifier Circuits

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Bistable Multivibrator (Flip−Flop)+V CCC 1R CR 1R 2TriggerinputR SCT 1OFFONT 2( a)– V BBVR CR 2– CC+V BBTriggerinputC 1R ONS CRT 11OFFT 2( b)Figure 7.37. A method of triggering unsymmetrically an NPN or a PNP transistor+V CCVTCR CD 3 R OFFONC D 2R 2D 3 R 2T 1D 1T 2CTD 1D 2T 1 T 2OFFON( a) ( b)Figure 7.38. Methods of symmetrical triggering through diodes at the collectors or the bases of the transistors7.5.4 Present Technology Bistable MultivibratorsThe bistable multivibrator (flip−flop) circuits we’ve discussed thus far are the original circuits andwere in use in the 1960s. We have included them in this text because they are the circuits fromwhich present technology bistable multivibrators such as those with CMOS technology and opamps have evolved. We will briefly discuss a bistable multivibrator with an op amp in this subsection.The circuit of Figure 7.39 shows how an op amp can be configured to behave as a bistable multivibrator.– BBElectronic Devices and Amplifier Circuits with MATLAB® / Simulink® / SimElectronics® Examples, Third EditionCopyright © Orchard Publications7−31
Chapter 7 Pulse Circuits and Waveform Generatorsv inCR1v outv inv outR 3The stable states for the bistable multivibrator of Figure 7.39(a) are the conditions where the outputis at positive or negative saturation. It assumes either positive or negative saturation by the positivefeedback formed by resistors and . A positive or negative going pulse as that shown inFigure 7.39(b) causes the circuit to switch states.7.6 Schmitt TriggerR 2( a)( b)Figure 7.39. Op amp configured as a bistable multivibratorR 2 R 3Another bistable multivibrator circuit is the Schmitt trigger shown in Figure 7.40(a).v sv outV +v outv outRR 1 2v sv sV ref( a)V + upper( b) ( c)V + lowerFigure 7.40. Schmitt trigger circuit and waveforms for increasing and decreasing input signalsThe Schmitt trigger circuit and transfer characteristics are similar to the comparator. It provides anvoltage when its input signal v sreaches some predetermined value set at the non−inverting inputof the op amp. The output of the op amp changes from the positive saturation voltage V out ( max)to its negative saturation voltage – V out ( max)and vice versa. As shown in Figure 7.40(b), the outputis positively saturated as long as the input signal v sis less than the upper threshold V + upper . Ifthe input signal v srises slightly above this threshold voltage, the output drop abruptly to– V out ( max)and stays there until v S drops below a lower threshold voltage V + lower . The thresholdvoltages V + upper and V + lower are determined by the resistors R 1 and R 2 , and the reference voltageV ref. These threshold voltages can be found by application of KCL at the non−inverting inputof the op amp. Thus,7−32Electronic Devices and Amplifier Circuits with MATLAB® / Simulink® / SimElectronics® Examples, Third EditionCopyright © Orchard Publications
Page 3 and 4: Electronic Devicesand Amplifier Cir
Page 5 and 6: PrefaceThis text is an undergraduat
Page 7 and 8: Table of Contents1 Basic Electronic
Page 9 and 10: 3.17 The Ebers−Moll Transistor Mo
Page 11 and 12: 6 Integrated Circuits6.1 Basic Logi
Page 13 and 14: A10.11 Exercises ..................
Page 15 and 16: 1.4 Bandwidth and Frequency Respons
Page 17 and 18: Chapter 1 Basic Electronic Concepts
Page 19 and 20: The Junction DiodeFigure 2.12. Volt
Page 21 and 22: The minus (−) sign for the curren
Page 23 and 24: 2.20 Solutions to End−of−Chapte
Page 25 and 26: The Bipolar Junction Transistor as
Page 27 and 28: Schottky Diode ClamporUsing the rel
Page 29 and 30: Chapter 4Field Effect Transistors a
Page 31 and 32: Metal Oxide Semiconductor Field Eff
Page 33 and 34: Op Amp Integrator1 tv C = --- iC C
Page 35 and 36: Chapter 5 Operational AmplifiersExa
Page 37 and 38: 5.29 Exercises1. For the circuit be
Page 39 and 40: NAND Gate1A114Vcc1A1B1Y1B1Y2313124B
Page 41 and 42: ExercisesV 1750 ΩT 1V 2750 Ω1 KΩ
Page 43 and 44: Astable Multivibrator with the 555
Page 45: Chapter 7 Pulse Circuits and Wavefo
Page 49 and 50: Chapter 8Frequency Characteristics
Page 51 and 52: k3 = 47.92f3 = 3.27 Hzw3 = 20.55 rp
Page 53 and 54: Chapter 9Tuned AmplifiersThis chapt
Page 55 and 56: Cascaded Tuned Amplifiersnary axis.
Page 57 and 58: Hartley Oscillatorpower supply volt
Page 59 and 60: Appendix AIntroduction to MATLAB®T
Page 61 and 62: Introduction to Simulink®Absolute
Page 63 and 64: Introduction to Simulink®An outsta
Page 65 and 66: Appendix DProportional−Integral
Page 67 and 68: Appendix FSubstitution, Reduction,
Page 69 and 70: IndexSymbols BiCMOS inverter 6-40 c
Page 71 and 72: Miller’s theorem F-10 phase shift

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