Ripple voltage refers to the small, unwanted AC voltage fluctuations that can occur in a DC power supply. These fluctuations are typically caused by incomplete suppression of the alternating current (AC) component during the conversion process from AC to direct current (DC). Ripple voltage can affect the performance of electronic devices, leading to noise and instability. In power supply design, engineers aim to minimize ripple voltage to ensure a stable output. This is often achieved using components like capacitors and inductors, which help smooth out the voltage. High ripple voltage can be detrimental to sensitive components, such as microcontrollers and sensors, which require a steady DC voltage for optimal operation.