Operational Amplifier Fundamentals Unit 3 – The Noninverting Amplifier
UNIT 3 – THE NONINVERTING AMPLIFIER
UNIT OBJECTIVE
At the completion of this unit, you will be able to demonstrate the dc and ac characteristics of a
noninverting operational amplifier by measuring circuit performance.
UNIT FUNDAMENTALS
A noninverting amplifier is a closed-loop op amp configuration. Feedback through R2 is
applied to the inverting terminal of the op amp. The input signal of the noninverting circuit is
applied to the noninverting terminal of the op amp.
Resistor R1 connects the inverting terminal of the op amp to circuit common. Circuit gain (Av)
equals 1 + (R2/R1). If R1 and R2 are equal, circuit gain equals 2.
In a noninverting configuration, the output and input voltage polarities are identical.
For proper operation (not in saturation), the differential input voltage (VD) of the op amp is
maintained at 0V. If the op amp is driven into saturation, VD cannot be maintained at 0V.