Catalog
High Efficiency Inductorless Step-Down DC/DC Converter
Key Features
• Input Voltage Range: 2.4V to 6V
• Fixed Output Voltages: 1.8V ±4%, 2V ±4%
• Output Current: Up to 100mA
• No Inductors
• Typical Efficiency 25% Higher than LDOs
• Low Operating Current: 25µA
• Low Shutdown Current: 5µA
• 600kHz Switching Frequency
• Shutdown Disconnects Load from VIN
• Soft-Start Limits Inrush Current at Turn-On
• Short-Circuit and Overtemperature Protected
• Available in 8-Pin MSOP and SO Packages
Description
AI
The LTC1503-1.8/LTC1503-2 are switched capacitor step-down DC/DC converters that produce a regulated output from a 2.4V to 6V input. The parts use switched capacitor fractional conversion to achieve high efficiency over the entire input range. No inductors are required. Internal circuitry controls the step-down conversion ratio to optimize efficiency as the input voltage and load conditions vary. Typical efficiency is 25% higher than that of a low dropout (LDO) linear regulator.Regulation is achieved by sensing the output voltage and enabling the internal switching network as needed to maintain a fixed output voltage. This method of regulation enables the parts to achieve high efficiency at extremely light loads. Low operating current (25µA with no load, 5µA in shutdown) and low external parts count (two 1µF flying capacitors and two 10µF bypass capacitors) make the LTC1503-1.8/LTC1503-2 ideally suited for space constrained battery-powered applications. The parts are fully short-circuit and over temperature protected.The LTC1503-1.8/LTC1503-2 are available in 8-pin MSOP and SO packages.ApplicationsCellular PhonesHandheld ComputersSmart Card ReadersLow Power DSP SuppliesPortable Electronic EquipmentHandheld Medical Instruments
