This compact (0.4? × 0.5?) switching step-down (or buck) voltage regulator takes input voltages between 4 V and 50 V and efficiently reduces them to a lower, user-adjustable voltage set by an on-board trimmer potentiometer. It has an output voltage range of 4 V to 25 V and a maximum output current of 600 mA. It has a very low dropout, so it can be used with input voltages that are within a few hundred millivolts of its output. The pins have a 0.1? spacing, making this board compatible with standard solderless breadboards and perfboards.