Op-Amp as Inverting Amplifier
Category: Operational Amplifier
Designer: RANA MUHAMMAD ADNAN KHALIL
Notes
This circuit is designed and simulated in Proteus 7.10. In this circuit you will learn how operational amplifier (op-amp) can be used as inverting amplifier. This circuit is very easy to understand and working is given below. 1. This circuit requires just four components, a variable resistor for input signal, two feedback resistors and any op-amp IC, LM324 op-amp IC is used in this circuit. 2. The +12VDC is applied to the VCC (pin 4) of op-amp and -12VDC is applied to the negative terminal of op-amp (pin 11). 3. The output of op-amp is connected with the inverting input of the op-amp using feedback resistor R1. 4. Resistor R2 is connected across inverting input and input signal (viper of variable resistor). 5. A viper of variable resistor is connected with the inverting input of the op-amp. 6. The non-inverting input of op-amp is connected with ground. 7. This configuration is known as inverting amplifier. 8. The gain of inverting amplifier is Gain = -R1/R2 Here R1 = 10K and R2 = 20K, therefore Gain = -10k/20k = -0.5 9. In this circuit, you will see the output is inverted and 0.5 times less than input, volt meters are placed at input and as well as output. 10. Therefore Vout = -(R1/R2)*Vin = -0.5*Vin. Applications: 1. This circuit is used as inverting amplifier for week signal. 2. This circuit can be used to adjust gain of any feedback signal. 3. This circuit can be used to scale up or scale down input signal.