CIRCUIT060024

This design inputs two signals, Vi1 and Vi2, and outputs their difference (subtracts). The input signals typically come from low-impedance sources because the input impedance of this circuit is determined by the resistive network. Difference amplifiers are typically used to amplify differential input signals and reject common-mode voltages. A common-mode voltage is the voltage common to both inputs. The effectiveness of the ability of a difference amplifier to reject a common-mode signal is known as commonmode rejection ratio (CMRR). The CMRR of a difference amplifier is dominated by the tolerance of the resistors.