The LTC3025 is a micropower, VLDO™(very low dropout) linear regulator which operates from input voltages as low as 0.9V. The device is capable of supplying 300mA of output current with a typical dropout voltage of only 45mV. A BIAS supply is required to run the internal reference and LDO circuitry while output current comes directly from the IN supply for high efficiency regulation. The low 0.4V internal reference voltage allows the LTC3025 output to be programmed to much lower voltages than available in common LDOs (range of 0.4V to 3.6V). The output voltage is programmed via two ultrasmall SMD resistors.The LTC3025’s low quiescent current makes it an ideal choice for use in battery-powered systems. For 3-cell NiMH and single cell Li-Ion applications, the BIAS voltage can be supplied directly from the battery while the input can come from a high efficiency buck regulator, providing a high efficiency, low noise output.Other features include high output voltage accuracy, excellent transient response, stability with ultralow ESR ceramic capacitors as small as 1μF, short-circuit and thermal overload protection and output current limiting. The LTC3025 is available in a tiny, low profile (0.75mm) 6-lead DFN (2mm × 2mm) package.Output CurrentOutput VoltageLTC3025300mAAdj (0.4V to 3.6V)LTC3025-1500mAAdj (0.4V to 3.6V)LTC3025-2500mA1.2V FixedLTC3025-3500mA1.5V FixedLTC3025-4500mA1.8V FixedAPPLICATIONSLow Power Handheld DevicesLow Voltage Logic SuppliesDSP Power SuppliesCellular PhonesPortable Electronic EquipmentHandheld Medical InstrumentsPost Regulator for Switching Supply Noise Rejection