When selecting a linear voltage regulator, you must prioritize the Dropout Voltage (Vdo), which is the minimum pressure difference between input and output required for regulation. For battery-powered devices, Low Dropout (LDO) versions are essential. Additionally, evaluate the Quiescent Current (Iq) to ensure energy efficiency, and the Power Supply Rejection Ratio (PSRR), which indicates the ability to filter out input noise—a critical factor for sensitive RF or audio applications. Ensure the Maximum Output Current meets your peak load requirements with at least a 20-30% safety margin.