WEBVTT

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>> In this video, I would like to summarize

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the function of the inverting op-amp amplifier.

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We start with our basic amplifier with the output coming out as shown.

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Then, we're going to run our feedback between the negative terminal and

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the output as shown here.

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This is going to be Rf for the feedback resistor,

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and then, we're going to connect our voltage source onto this feedback loop right here,

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the Vs and the Rs terms.

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This is going down to ground.

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Then on the positive side,

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we're going to ground that positive terminal right there.

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Often, V out might be over some load resistance like this.

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So in this case, V out is going to be equal to Vs,

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times minus Rf divided by Rs.

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Again, we have Vcc and minus Vcc powering this op-amp.

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So, V0 is limited between the range of minus Vcc and plus Vcc.

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Let's write this as gain.

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V0 is equal to the gain times Vs,

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and for this amplifier,

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the gain is minus Rf divided by Rs.

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The negative term right here,

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tells us that this is an inverting op-amp amplifier.

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We can see, that Rf and Rs could be greater than one,

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equal to one, or less than one.

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So, the gain can be either positive or negative.

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Sorry, the gain is going to be negative because it's going to be inverting.

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That the gain can either increase or decrease our amplification.

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We can draw our amplifier the same way.

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We can say Vs and put it into a multiplier,

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multiply it by the gain.

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That gives us our V out value.