The LT1521CST-3.3#PBF is a 3.3V fixed output low-dropout (LDO) Linear Regulator with micropower quiescent current and shutdown. This device is capable of supplying 300mA of output current with a dropout voltage of 0.5V. The low quiescent current, 12uA operating and 6uA in shutdown, makes them an ideal choice. The quiescent current is well controlled, it does not rise in dropout as it does with many other low-dropout (LDO) PNP regulators. Other features of the device include the ability to operate with very small output capacitors. Also the input may be connected to voltages lower than the output voltage, including negative voltages, without reverse current flow from output to input. This makes the device ideal for backup power situations where the output is held high and the input is low or reversed. Under these conditions only 5uA will flow from the output pin to ground.
