Applications of Operational Amplifiers: Analog Inverter and Scale Changer

Analog Inverter and Scale Changer: The circuit of analog inverter is shown in fig. 1. It is same as inverting voltage amplifier. Assuming OPAMP to be an ideal one, the differential input voltage is zero. i.e. vd = 0 Therefore, v1 = v2 = 0 Since input impedance is very high, therefore, input current is zero. OPAMP do not sink any current. \ iin= ifvin / R = - vO / Rfvo = - (Rf / R) vin If R = Rf then vO = -vin, the circuit behaves like an inverter. If Rf / R = K (a constant) then the circuit is called inverting amplifier or scale changer voltages. Fig. 1