2.1 Introduction,Electronic systems based on analog principles form an important class of electronic devices. The frequency-modulated (FM) receiver is one common example of analog electronic systems. Although modern receivers contain certainly digital components as well, the transmitted signal is analog. The input to an FM receiver is a FM signal. The signal is an analog, that is, it is a continuous function of time and can have any amplitude. Many electrical instruments, e.g. voltmeters, ammeters, wattmeter and oscilloscopes also utilize analog techniques, at least in part.,2.2 Operational Amplifiers,2.2.1 Integrated-circuit Ampliying Systems 2.2.2 Properties and Construction 2.2.3 Schematic Symbol of An Op-amp,2.2.1 Integrated-circuit Ampliying Systems,A number of manufacturers market amplifying systems in integrated-circuit packages. A wide range of different intergrated circuits (ICs) are available. Some of these are designed to perform one specific system function. This includes such things as preamplifiers, linear signal amplifiers, and power amplifiers. Other ICs may perform as a complete system. Electrical power for operation and only a limited number of external components are needed to complete the system. Low-power audio amplifiers and stereo amplifiers are examples of these devices.,2.2.2 Properties and Construction,Fig.2-1 Simplified diagram of the internal functions of an op-amp diagram,2.2.3 Schematic Symbol of An Op-amp,Fig.2-2 Schematic symbol of an op-amp,2.2.3 Schematic Symbol of An Op-amp,Fig.2-3 Inverting DC amplifiers,2.3 Differential and Instrumentation Amplifiers,2.3.1 Differential Amplifier 2.3.2 Instrumentation-Quality Differential Amplifier,2.3.1 Differential Amplifier,Fig.2-4 Differential amplifier,2.3.2 Instrumentation-Quality Differential Amplifier,Fig.2-5 Instrumentation-quality differential amplifier,2.4 Integrator and Differentiator,2.4.1 Integrator Circuit 2.4.2 Differentiator Circuit,2.4.1 Integrator Circuit,Fig.2-6 Schematic diagram of an integrator,2.4.2 Differentiator Circuit,Fig.2-7 Schematic diagram of a differentiator,2.5 Active Filters,1. analog 2. feedback 3. linearity 4. integrated-circuit 5. amplifier 6. component 7. couple 8. transistor 9. silicon 10. package 11. gain 12. capability,2.5 Active Filters,13. impedance 14. bandwidth 15. label 16. resistor 17. zener 18. heat 19. terminal 20. power 21. schematic 22. minus 23. plus 24.inverting,2.5 Active Filters,25.noninverting 26. differential 27. rejection 28. integrator 29. differentiator 30. capacitor 31. constant 32. bias 33. passive 34. active 35. implement 36. magnitude,2.5 Active Filters,37. cascade 38. cut-off,2.5 Active Filters,Fig.2-8 Transfer-function magnitude versus frequency for lowpass Butterworth filter,2.5 Active Filters,Fig.2-9 Sallen-key lowpass filter,