The AP2318 is a series of ultra low dropout regulators optimized for low voltage applications where transient response and minimum input voltage are critical. The AP2318 provides current limit and thermal shutdown. Its circuit includes a trimmed bandgap reference to assure output voltage accuracy to be within ±1.5%. On-chip thermal shutdown provides protection against any combination of overload and ambient temperatures that would create excessive junction temperatures. The AP2318 has both fixed and adjustable versions. The 1.3V fixed versions integrate the corresponding resistor divider. The adjustable version can set the output voltage through two external resistors.