特点
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 V
IN
Adjustable Output Voltage Range: 0.9V to 1.6V
Fixed Output Voltages: 1.2V, 1.5V
Super Burst, Burst and Burst Defeat Operating Modes
Low Operating Current: I
IN
= 35μA (Burst Mode? Operation)
Super Burst Operating Current: I
IN
= 10μA
Low Shutdown Current: I
IN
= 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
典型应用
典型应用
描述
The LTC?3251/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. V OUT is 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 overtemperature protected, and are available in a thermally enhanced 10-pin MSOP package.
*U.S. Patent #6, 411, 531