Analog Devices Inc./Maxim Integrated

The LT1579 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.The LT1579 can supply 300mA of output current from either input at a dropout voltage of 0.4V. 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 reverse-current 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. The LT1579 regulators are available in narrow 16-lead SO and 16-lead SSOP packages with all features, and in SO-8 with limited features.ApplicationsDual Battery SystemsBattery Backup SystemsAutomatic Power Management for Battery-Operated Systems

The LT®1584/LT1585/LT1587 are low dropout three-terminal regulators with 7A, 4.6A and 3A output current capability, respectively. Design has been optimized for low voltage applications where transient response and minimum input voltage are critical. Similar to the LT1083/4/5 family, it has lower dropout voltage and faster transient response. These improvements make it ideal for low voltage microprocessor applications requiring a regulated 2.5V to 3.6V output with an input supply below 7V.Current limit is trimmed to ensure specified output current and controlled short-circuit current. On-chip thermal limiting provides protection against any combination of overload that would create excessive junction temperatures.The LT1585/LT1587 are available in both the through-hole and surface mount versions of the industry standard 3-pin TO-220 power package. The LT1584 is available in the through-hole 3-pin TO-220 power package.Output CurrentOutput Voltage OptionsLT1584, -3.3, -3.38, -3.45, -3.67AAdj, 3.3V, 3.38V, 3.45V, 3.6VLT1585, -3.3, -3.38, -3.45, -3.64.6AAdj, 3.3V, 3.38V, 3.45V, 3.6VLT1585A, LT1585A-3.35AAdj, 3.3VLT1585-1.5, LT1585A-1.54.6A / 5AFixed 1.5VLT1587, -3.3, -3.45, -3.63AAdj, 3.3V, 3.45V, 3.6VLT1587-1.53AFixed 1.5VApplicationsPentium™Processor SuppliesPowerPC™SuppliesOther 2.5V to 3.6V Microprocessor SuppliesLow Voltage Logic SuppliesBattery-Powered CircuitryPost Regulator for Switching Supply

The LT1585-1.5/LT1585A-1.5 are low dropout, 3-terminal regulators with 4.6A and 5A output current capability respectively, and a fixed 1.5V output voltage. The designs are optimized for low voltage applications where transient response and minimum input voltage are critical. Similar to the LT1084, they have lower dropout and faster transient response. These improvements make them ideal for low voltage microprocessor applications, especially as the regulator in an Intel processor GTL+ supply.Current limit is trimmed to ensure specified output current and controlled short-circuit current. On-chip thermal limiting provides protection against any combination of overload that creates excessive junction temperatures.The LT1585-1.5/LT1585A-1.5 are available in the through-hole 3-pin TO-220 power package and 3-pin plastic DD.Output CurrentOutput Voltage OptionsLT1584, -3.3, -3.38, -3.45, -3.67AAdj, 3.3V, 3.38V, 3.45V, 3.6VLT1585, -3.3, -3.38, -3.45, -3.64.6AAdj, 3.3V, 3.38V, 3.45V, 3.6VLT1585A, LT1585A-3.35AAdj, 3.3VLT1585-1.5, LT1585A-1.54.6A/5AFixed 1.5VLT1587, -3.3, -3.45, -3.63AAdj. 3.3V, 3.45V, 3.6VLT1587-1.53AFixed 1.5VApplicationsGTL+ Power SupplyLow Voltage Logic SuppliesBattery-Powered Circuitry

The LT1585-1.5/LT1585A-1.5 are low dropout, 3-terminal regulators with 4.6A and 5A output current capability respectively, and a fixed 1.5V output voltage. The designs are optimized for low voltage applications where transient response and minimum input voltage are critical. Similar to the LT1084, they have lower dropout and faster transient response. These improvements make them ideal for low voltage microprocessor applications, especially as the regulator in an Intel processor GTL+ supply.Current limit is trimmed to ensure specified output current and controlled short-circuit current. On-chip thermal limiting provides protection against any combination of overload that creates excessive junction temperatures.The LT1585-1.5/LT1585A-1.5 are available in the through-hole 3-pin TO-220 power package and 3-pin plastic DD.Output CurrentOutput Voltage OptionsLT1584, -3.3, -3.38, -3.45, -3.67AAdj, 3.3V, 3.38V, 3.45V, 3.6VLT1585, -3.3, -3.38, -3.45, -3.64.6AAdj, 3.3V, 3.38V, 3.45V, 3.6VLT1585A, LT1585A-3.35AAdj, 3.3VLT1585-1.5, LT1585A-1.54.6A/5AFixed 1.5VLT1587, -3.3, -3.45, -3.63AAdj. 3.3V, 3.45V, 3.6VLT1587-1.53AFixed 1.5VApplicationsGTL+ Power SupplyLow Voltage Logic SuppliesBattery-Powered Circuitry