The MAX1818 low-dropout linear regulator operates from a +2.5V to +5.5V supply and delivers a guaranteed 500mA load current with low 120mV dropout. The high-accuracy (±1%) output voltage is preset at an internally trimmed voltage (see Selector Guide in the full data sheet) or can be adjusted from 1.25V to 5.0V with an external resistive divider. An internal PMOS pass transistor allows the low 125µA supply current to remain independent of load, making this device ideal for portable battery-operated equipment such as personal digital assistants (PDAs), cellular phones, cordless phones, base stations, and notebook computers. Other features include an active-low open-drain reset output that indicates when the output is out of regulation, a 0.1µA shutdown, short-circuit protection, and thermal shutdown protection. The device is available in a miniature 800mW 6-pin SOT23 package.