Which statement best describes the primary purpose of signal conditioning between sensors and ADCs?

• A. To match impedance, amplify small signals, filter noise, scale levels to the ADC input range, and improve accuracy.
• B. To convert digital signals to analog form.
• C. To shorten the cable length between sensor and ADC.
• D. To increase the motor torque directly.

Answer: (A)

Signal conditioning prepares the sensor output so the ADC can read it accurately. It does this by matching the source impedance to the ADC input, preventing the sensor from being loaded and preserving the true signal. It amplifies small signals so they use more of the ADC’s dynamic range, which improves resolution and reduces quantization error. It filters out noise and unwanted frequency components to prevent them from corrupting the measurement. It scales and level-shifts the signal to fit the ADC’s input range, ensuring the full-scale counts are used for the measurement. These steps collectively improve accuracy, signal integrity, and reliability of the measurement. Converting digital to analog would be the opposite of what’s happening here, and while shorter cable lengths or actuator effects can influence performance, they are not the primary purpose of signal conditioning.