
We selected the R1 resistor value as 1.2k, We will find out the value of Rf or R2 resistor and will calculate the output voltage after amplification.Īs the gain is dependent on the resistors and the formula is Av = 1 + (Rf / R1) We will configure the op-amp in noninverting configuration with 3x gain capabilities. We will design a non-inverting op-amp circuit which will produce 3x voltage gain at the output comparing the input voltage. Practical Example of Non-inverting Amplifier Op-amp can also be used two add voltage input voltage as summing amplifier.

In reality, it is widely dependent on the op-amp behavior and open-loop gain. And if the R1 becomes 0, then the gain will be infinity. Now, Interesting thing is, if we put the value of feedback resistor or Rf as 0, the gain will be 1 or unity. The gain is directly dependent on the ratio of Rf and R1. Also, the gain will be positive and it cannot be in negative form. So, by this factor, the op-amp gain cannot be lower than unity gain or 1. Using this formula we can conclude that the closed loop voltage gain of a Non- Inverting operational amplifier is, Av = Vout / Vin = 1 + (Rf / R1)

The total voltage gain of the amplifier (Av) is Vout / Vin So, Av = Vout / Vin = (R1 + Rf) / R1 The Voltage divider output which is fed into the non-inverting pin of the amplifier is equal to the Vin, as Vin and voltage divider’s junction points are situated across the same ground node.ĭue to this, and as the Vout is dependent on the feedback network, we can calculate the closed loop voltage gain as below.Īs Voltage Divider output Voltage is same as input Voltage, Divider Vout = Vin So, Vin / Vout = R1 / (R1 + Rf) Or, Vout / Vin = (R1 + Rf) / R1 R2 is referred to as Rf ( Feedback resistor) The amplification is dependent on those two feedback resistors ( R1 and R2) connected as the voltage divider configuration. In an ideal condition, the input pin of the op-amp will provide high input impedance and the output pin will be in low output impedance. These two resistors are providing required feedback to the op-amp. The signal which is needed to be amplified using the op-amp is feed into the positive or Non-inverting pin of the op-amp circuit, whereas a Voltage divider using two resistors R1 and R2 provide the small part of the output to the inverting pin of the op-amp circuit. In the upper image, an op-amp with Non-inverting configuration is shown. Non-inverting Operational Amplifier Configuration This is generally achieved by applying a small part of the output voltage back to the inverting pin (In case of non-inverting configuration) or in the non-inverting pin (In case of inverting pin), using a voltage divider network. Due to this, the amplified output become “ in- phase” with the input signal.Īs we discussed before, Op-amp needs feedback to amplify the input signal. In the non-inverting configuration, the input signal is applied across the non-inverting input terminal ( Positive terminal) of the op-amp.
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In this tutorial, we will learn how to use op-amp in noninverting configuration. An op-amp amplifies the difference in voltage between this two input pins and provides the amplified output across its Vout or output pin.ĭepending on the input type, op-amp can be classified as Inverting or Non-inverting. Those two differential input pins are inverting pin or Negative and Non-inverting pin or Positive. You can learn more about Op-amps by following our Op-amp circuits section.Īn op-amp has two differential input pins and an output pin along with power pins. LM358, LM741, LM386 are some commonly used Op-amp ICs. There are plenty of op-amps available in different integrated circuit (IC) package, some op-amp ic’s has two or more op-amps in a single package. Different class of op-amps has different specifications depending on those variables. An op-amp circuit consists of few variables like bandwidth, input, and output impedance, gain margin etc.

Op-Amps are popular for its versatility as they can be configured in many ways and can be used in different aspects. An operational amplifier is a DC-coupled electronic component which amplifies Voltage from a differential input using resistor feedback. Op-Amp, short for operational amplifier is the backbone of Analog electronics.
