Lec 1 Intro OpAmp PDF

Introduction DR SHERIEF FATHY  Lecture Outline  Passive components  Ohm Law  Symbol Convention « AC , DC , (AC+DC) »  Amplifiers  Operational Amplifier (Op-Amp) 2 Passive components: Resistors(R), Capacitors (C), and Inductors (L)...

Introduction DR SHERIEF FATHY  Lecture Outline  Passive components  Ohm Law  Symbol Convention « AC , DC , (AC+DC) »  Amplifiers  Operational Amplifier (Op-Amp) 2 Passive components: Resistors(R), Capacitors (C), and Inductors (L) 3  Ohm Law VR = IR * R V+ = V- + IR * R V+ V- V- = V+ - IR * R IR = (V+ - V-) / R Example: Let: RD = 1KΩ IR = (V+ - V-) / RD = (VDD – VD) / RD = (5-0.1)/1K = 4.9mA 4  Symbol Convention AC , DC , (AC+DC) The total instantaneous current iC(t) is the sum of the dc current IC and the ac signal current ic(t). where the ac signal current is given by: 5  Amplifiers Most amplifiers are primarily intended to operate on very small input signals. Their purpose is to make the signal magnitude larger, and therefore they are thought of as voltage amplifiers. Amplifier Circuit Symbol 6 Voltage Amplifiers 7 Voltage, Current, and Power Gains 1. Voltage Gain 2. Current Gain 3. Power Gain 8 Expressing Gain in Decibels 9  The Amplifier Power Supplies DC Power PDC: Total Input Power = Total Output Power Amplifier Efficiency: 10 Amplifier Saturation 11 Circuit’s Input / Output Resistances 𝒗𝒙 𝑹𝒊𝒏 = 𝒊𝒙 𝒗𝒙 𝑹𝒐𝒖𝒕 = 𝒊𝒙 ; vin = 0 (S.C.) 12 Operational Amplifier (Op-Amp) General Equivalent Circuit of Op-Amp 13 IDEAL OP-AMP A is called the differential gain, another name that we will attach to A: the open-loop gain. 14  IDEAL OP-AMP 𝑽+ = 𝑽− 𝒊+ = 𝒊− = 𝟎 15  Revision These topics are required as a prerequisite for this course: Kirchhoff Current Law (KCL) Kirchhoff Voltage Law (KVL) Thevenin Theorem Superposition Theorem 16 References 17 End of the Lecture 18