What is an important characteristic of a VCO in applications?

A Voltage-Controlled Oscillator (VCO) is designed to produce an output frequency that varies in response to changes in input voltage. This characteristic is crucial in applications such as phase-locked loops and frequency modulation, where precise control over frequency is necessary based on an input signal. The purpose of a VCO is to translate voltage changes into frequency changes, enabling versatile applications in communication systems, signal processing, and other electronics where modulation and signal generation are required.

The other characteristics listed, while important in different aspects of circuit design, do not specifically define the primary function of a VCO. Consistency in output voltage is more associated with voltage regulators, while an output frequency that does not depend on external factors describes fixed oscillators. The ability to handle high power signals pertains to amplifiers or high-frequency transmitters rather than the core behavior of VCOs. Thus, the defining feature of a VCO is its output frequency's dependence on input voltage changes.