The MAX1806 low-dropout linear regulator operates from a +2.25V to +5.5V supply and delivers a guaranteed 500mA load current with low 175mV dropout. The high-accuracy (1%) output voltage is preset at an internally trimmed voltage (see Selector Guide) or can be adjusted from +0.8V to +4.5V with an external resistive-divider. An internal PMOS pass transistor allows low 210A supply current, making this device ideal for portable equipment such as personal digital assistants (PDAs), cellular phones, cordless phones, and other equipment, including base stations and docking stations. Other features include an active-low, power-OK output that indicates when the output is out of regulation, a 0.02A shutdown mode, short-circuit protection, and thermal shutdown protection. The MAX1806 comes in a miniature 1.3W, 8-pin power-MAX package with a metal pad on the underside of the package.