Adafruit 5.0V 250mA Linear Voltage Regulator - L4931-5.0 TO-92

The L4931 from ST is a reliable 5V low-dropout regulator, shrinking input voltages of 5.5-20V to a stable 5V output with 2% regulation. Encased in a TO-92 package, it provides up to 300mA current, featuring internal current limiting and thermal shutdown protection.

This regulator's impressive 0.4V dropout is a standout, easily surpassing the performance of typical 780X series regulators. Ideal for transforming a 9V supply to a smooth 5V, it maintains a quiescent current draw of just 1mA, suitable for battery-driven and portable electronics.

When implementing, ensure the L4931 is equipped with a minimum of 2.2uF electrolytic capacitors for both input and output stability, with 10uF being optimal. Its thermal resistance of 200°C/Watt necessitates careful power management, particularly in setups exceeding 0.6W dissipation without a heatsink.

Practical examples include pairing with four AA batteries for a 6V input, allowing an output current of 0.2A while maintaining manageable heat levels of 0.2W. This sturdy component is a pivotal choice for ensuring stable power in diverse electronic projects.