What term describes the ability of a differential amplifier to minimize signals that are present on both inputs?

What term describes the ability of a differential amplifier to minimize signals that are present on both inputs?

• A. Signal-to-noise ratio
• B. Analog-to-digital converter
• C. Common mode rejection
• D. Impedance

Answer: (C)

Common-mode rejection describes the ability of a differential amplifier to suppress signals that appear on both inputs. A differential amplifier is designed to amplify only the difference between its two inputs, so any signal present identically on both leads—the common-mode signal—gets attenuated. The stronger this rejection, the less interference from noise or unrelated signals that are common to both inputs, while the actual difference signal is preserved. This is why high common-mode rejection (often expressed as a high CMRR) is crucial in accurately measuring small differential signals against pervasive electrical noise. SNR relates to overall signal quality versus noise in the system, not specifically to canceling identical inputs. An analog-to-digital converter is a device that converts continuous signals to digital form, not about rejecting common-mode signals. Impedance is about resistance to current flow at a given frequency and doesn’t describe suppression of signals common to both inputs.

Common-mode rejection describes the ability of a differential amplifier to suppress signals that appear on both inputs. A differential amplifier is designed to amplify only the difference between its two inputs, so any signal present identically on both leads—the common-mode signal—gets attenuated. The stronger this rejection, the less interference from noise or unrelated signals that are common to both inputs, while the actual difference signal is preserved. This is why high common-mode rejection (often expressed as a high CMRR) is crucial in accurately measuring small differential signals against pervasive electrical noise.

SNR relates to overall signal quality versus noise in the system, not specifically to canceling identical inputs. An analog-to-digital converter is a device that converts continuous signals to digital form, not about rejecting common-mode signals. Impedance is about resistance to current flow at a given frequency and doesn’t describe suppression of signals common to both inputs.