FEATURES
s s s s s s s s s s s s s DESCRIPTION
The LT®1579 is a dual input, single output, low dropout regulator. This device is designed to provide an uninterruptible output voltage from two independent input voltage sources on a priority basis. All of the circuitry needed to switch smoothly and automatically between inputs is incorporated. Quiescent current is 50µA, dropping to 7µA in shutdown. Two comparators are included to monitor input voltage status. Two additional status flags indicate which input is supplying power and provide an early warning against loss of output regulation when both inputs are low. A secondary select pin is provided so that the user can force the device to switch from the primary input to the secondary input. Internal protection circuitry includes reverse-battery protection, current limiting, thermal limiting and reversecurrent protection. The device is available in fixed output voltages of 3V, 3.3V and 5V, and as an adjustable device with a 1.5V reference voltage.