PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Kristin Ackerson, Virginia Tech EEKristin Ackerson, Virginia Tech EESpring 2002Spring 2002__++Table of ContentsTable of ContentsKristin Ackerson, Virginia Tech EEKristin Ackerson, Virginia Tech EESpring 2002Spring 2002The Operational Amplifier______________________________slides 3-4The Operational Amplifier______________________________slides 3-4The Four Amplifier Types______________________________slide 5The Four Amplifier Types______________________________slide 5VCVS(Voltage Amplifier) Summary:VCVS(Voltage Amplifier) Summary:Noninverting Configuration____________slides 6-9Noninverting Configuration____________slides 6-9Inverting Configuration________________slides 10-12Inverting Configuration________________slides 10-12ICIC(Current Amplifier) Summary________________________slide 13 ICIC(Current Amplifier) Summary________________________slide 13 VCIS (Transconductance Amplifier) Summary_____________slides 14-15VCIS (Transconductance Amplifier) Summary_____________slides 14-15ICVS (Transresistance Amplifier) Summary_______________slides 16-18ICVS (Transresistance Amplifier) Summary_______________slides 16-18Power Bandwidth_____________________________________slide 19Power Bandwidth_____________________________________slide 19Slew Rate____________________________________________slide 20Slew Rate____________________________________________slide 20Slew Rate Output Distortion____________________________ slide 21Slew Rate Output Distortion____________________________ slide 21Noise Gain___________________________________________slide 22Noise Gain___________________________________________slide 22Gain-Bandwidth Product_______________________________slide 23Gain-Bandwidth Product_______________________________slide 23Cascaded Amplifiers - Bandwidth________________________slide 24Cascaded Amplifiers - Bandwidth________________________slide 24Common Mode Rejection Ratio__________________________slides 25-26Common Mode Rejection Ratio__________________________slides 25-26Power Supply Rejection Ratio___________________________slide 27Power Supply Rejection Ratio___________________________slide 27Sources_____________________________________________slide 28Sources_____________________________________________slide 28The Operational AmplifierThe Operational AmplifierKristin Ackerson, Virginia Tech EEKristin Ackerson, Virginia Tech EESpring 2002Spring 2002•Usually Called Op AmpsUsually Called Op Amps•An amplifier is a device that accepts a varying input signal and An amplifier is a device that accepts a varying input signal and produces a similar output signal with a larger amplitude.produces a similar output signal with a larger amplitude.•Usually connected so part of the output is fed back to the input. Usually connected so part of the output is fed back to the input. (Feedback Loop)(Feedback Loop)•Most Op Amps behave like voltage amplifiers. They take an input Most Op Amps behave like voltage amplifiers. They take an input voltage and output a scaled version.voltage and output a scaled version.•They are the basic components used to build analog circuits.They are the basic components used to build analog circuits.•The name “operational amplifier” comes from the fact that they The name “operational amplifier” comes from the fact that they were originally used to perform mathematical operations such as were originally used to perform mathematical operations such as integration and differentiation.integration and differentiation.•Integrated circuit fabrication techniques have made high-Integrated circuit fabrication techniques have made high-performance operational amplifiers very inexpensive in comparison performance operational amplifiers very inexpensive in comparison to older discrete devices.to older discrete devices.•ii(+)(+), i, i(-)(-) : Currents into the amplifier on the inverting and noninverting lines : Currents into the amplifier on the inverting and noninverting lines respectivelyrespectively•vvidid : The input voltage from inverting to non-inverting inputs : The input voltage from inverting to non-inverting inputs•+V+VSS , -V , -VSS : DC source voltages, usually +15V and –15V : DC source voltages, usually +15V and –15V•RRii : The input resistance, ideally infinity : The input resistance, ideally infinity•A : The gain of the amplifier. Ideally very high, in the 1x10A : The gain of the amplifier. Ideally very high, in the 1x101010 range. range.•RROO: The output resistance, ideally zero: The output resistance, ideally zero•vvOO: The output voltage; v: The output voltage; vOO = A = AOLOLvvidid where A where AOLOL is the open-loop voltage gain is the open-loop voltage gainThe Operational AmplifierThe Operational AmplifierKristin Ackerson, Virginia Tech EEKristin Ackerson, Virginia Tech EESpring 2002Spring 2002+V+VSS-V-VSSvvididInvertingInvertingNoninvertingNoninvertingOutputOutput++__ii(-)(-)ii(+)(+)vvOO = A = AddvvididRROOAARRiiThe Four Amplifier TypesThe Four Amplifier TypesKristin Ackerson, Virginia Tech EEKristin Ackerson, Virginia Tech EESpring 2002Spring 2002DescriptionGain SymbolTransfer FunctionVoltage Amplifieror Voltage Controlled Voltage Source (VCVS)Avvo/vinCurrent Amplifieror Current Controlled Current Source (ICIS)Aiio/iinTransconductance AmplifierorVoltage Controlled Current Source (VCIS)gm(siemens)io/vinTransresistance AmplifierorCurrent Controlled Voltage Source (ICVS)rm(ohms)vo/iinVCVS (Voltage Amplifier) SummaryVCVS (Voltage Amplifier) SummaryKristin Ackerson, Virginia Tech EEKristin Ackerson, Virginia Tech EESpring 2002Spring 2002Noninverting ConfigurationNoninverting Configuration++__vvinin++++--vvOOvvididii(+)(+)ii(-)(-)iiOOiiFFRRFFRRLLRR11ii11vvidid = v = voo/A/AOLOLAssuming AAssuming AOLOL   vvidid =0 =0Also, with the Also, with the assumption that Rassumption that Rinin = = ii(+)(+) = i = i(-)(-) = 0 = 0__vvFF++__vv11++__vvLL++__iiLLApplying KVL the Applying KVL the following equations following equations can be found:can be found:vv11 = v = vininvvOO = v = v11 + v + vFF = v = vinin+ i+ iFFRRFFThis means that, This means that, iiFF = i = i11Therefore: iTherefore: iFF = v = vinin/R/R11Using the equation to the left the output Using the equation to