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OPerational AMPlifier OPAMP

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AGENDA

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OPAMP COMPONENTOverviewSymbol and packageConnectionsInternalPower connectionsVcc and Vee examplesRemmber 5 ideal rulesRemember real opampFeedback

BUFFERnity Gain, +1 Amp, Voltage FollowerTransfer curveApplicationINVERTING AMPLIFIERVirtual groundNON-INVERTING AMPLIFIERSUMMING AMPLIFIERSumming junctionDA SUMMING AMPLIFIERVARIABLE AMPLIFIERDIFFERENTIAL AMPLIFIER

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OPAMP

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Course content OPAMP

Analog Electronics T.E. Price

OPAMP component page xxxNon- inverting amplifier page 427Inverting amplifier page 433Summing amplifier page xxxDifference amplifier page 441

Problems: chapter 13; 3,7,10,11,12,14,15

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OPAMP, symbol and package

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OPAMP, connections

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+V = Vcc = most positive power supply-V = Vee= most negative power supplyV+ = non-inverting inputV- = inverting inputOutput = output

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OPAMP, internal

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+V = Vcc-V = VeeV+ = non-inverting inputV- = inverting inputOutput = output

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OPAMP, power connections

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OPAMP, Vcc and Vee, examples

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OPAMP,remember

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OPAMP, real world

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OPAMP, feedback

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OPAMP, feedback

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Uout = Au (U+-U-)Uout = 200.000 (U+-U-)

Differential input voltage= ΔU = 0 !!! Only for negative Feedback

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OPAMP,feedback

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The circuit will quickly reach a point of stability the output voltage is just the right amount of differential voltage accoding to the Au.

Taking the op-amp's output voltage and coupling it to the inverting input is a technique known as negative feedback, and it is the key to having a self-stabilizing system.

Because the op-amp's gain is so high, the voltage on the inverting input can be maintained almost equal to Vin. The output terminal, and the system holds there in balance.

The higher the op-amp differential gain, the closer that differential voltage will be to zero.

ΔU = 0

OnlyForNegativeFeedback

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Buffer, Unity Gain +1Voltage follower

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Rin = ∞ Rout = 0 Uin = Uout

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Buffer, transfer curve

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inout VV

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Buffer, application

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Accurate voltage divider, Rload = ∞, Iin = 0

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Inverting amplifier

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Inverting amplifier

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Invertingamplifier

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VirtualGround

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Virtual = no currentGround = 0 volt

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Non-inverting amplifier

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Non-inverting amplifier

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Non-invertingamplifier

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Summingjunction

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Summingamplifier

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3 bitDASummingamplifier

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6 bitsDASumming

amplifier

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Summing amplifier

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Variable amplifier

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Differential amp

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For R1 = R3And R2 = R4

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Instrumentationamplifier

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Instrumentationamplifier

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Rin = ∞Gain = R1