LTC3251 Series

500mA High Efficiency, Low Noise, Inductorless Step-Down DC/DC Converters

Catalog

500mA High Efficiency, Low Noise, Inductorless Step-Down DC/DC Converters

Part	Output Type	Voltage - Input (Max) [Max]	Supplier Device Package	Voltage - Output (Min/Fixed)	Frequency - Switching [Min]	Frequency - Switching [Max]	Synchronous Rectifier	Mounting Type	Output Configuration	Function	Voltage - Input (Min) [Min]	Number of Outputs	Package / Case	Package / Case	Current - Output	Operating Temperature [Max]	Operating Temperature [Min]	Output Type	Voltage - Output (Max) [Max]
Analog Devices LTC3251EMSE-1.5#PBF	1.81 mOhm	5.5 V	10-MSOP-EP	1.5 V	1 MHz	1.6 MHz		Surface Mount	Positive	Step-Down	2.7 V	1	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	500 mA	85 °C	-40 °C
Analog Devices LTC3251EMSE#TRPBF		5.5 V	10-MSOP-EP	0.9 V	1 MHz	1.6 MHz		Surface Mount	Positive	Step-Down	2.7 V	1	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	500 mA	85 °C	-40 °C	Adjustable	1.6 V

Catalog

500mA High Efficiency, Low Noise, Inductorless Step-Down DC/DC Converters

Key Features

• Up to 500mA Output Current

• No Inductors

• 2.7V to 5.5V Input Voltage Range

• 2x Efficiency Improvement Over LDOs

• 2-Phase, Spread Spectrum Operation for Low Input and Output Noise

• Shutdown Disconnects Load from VIN

• Adjustable Output Voltage Range: 0.9V to 1.6VFixed Output Voltages: 1.2V, 1.5V

• Fixed Output Voltages: 1.2V, 1.5V

• Super Burst, Burst and Burst Defeat Operating Modes

• Low Operating Current: IIN= 35µA (Burst Mode®Operation)

• Super Burst Operating Current: IIN= 10µA

• Low Shutdown Current: IIN= 0.01µA Typ

• Soft-Start Limits Inrush Current at Turn-On

• Short-Circuit and Overtemperature Protected

• Available in a Thermally Enhanced 10-Pin MSOP Package

Description

The LTC3251/LTC3251-1.2/LTC3251-1.5 are 2-phase charge pump step-down DC/DC converters that produce a regulated output from a 2.7V to 5.5V input. The parts use switched capacitor fractional conversion to achieve twice the typical efficiency of a linear regulator. No inductors are required. VOUTis resistor programmable from 0.9V to 1.6V or fixed at 1.2V or 1.5V, with up to 500mA of load current available.A unique 2-phase spread spectrum architecture provides a very low noise regulated output as well as low noise at the input. The parts have four operating modes: Continuous Spread Spectrum, Spread Spectrum with Burst Mode operation, Super Burst™mode operation and shutdown.Low operating current (35µA in Burst Mode operation, 10µA in Super Burst mode operation) and low external parts count make the LTC3251/LTC3251-1.2/LTC3251-1.5 ideally suited for space-constrained battery-powered applications. The parts are short-circuit and over-temperature protected, and are available in a thermally enhanced 10-pin MSOP package.ApplicationsHandheld DevicesCellular PhonesPortable Electronic EquipmentDSP Power Supplies