特点
Low Noise Constant Frequency Operation
2.7V to 5.5V Input Voltage Range
No Inductors
Typical Efficiency 25% Higher Than LDOs
Shutdown Disconnects Load from V
IN
Output Voltage: 1.8V ±4% or 1.5V ±4%
Output Current: 250mA
Low Operating Current: I
IN
= 180μA Typ
Low Shutdown Current: I
IN
= 10μA Typ
Oscillator Frequency: 1.5MHz
Soft-Start Limits Inrush Current at Turn On
Short-Circuit and Overtemperature Protected
Available in an 8-Pin MSOP Package
典型应用
典型应用
描述
The LTC ? 1911 is a switched capacitor step-down DC/DC converter that produces a 1.5V or 1.8V regulated output from a 2.7V to 5.5V input. The part uses 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 over 25% higher than that of a linear regulator.
A unique constant frequency architecture provides a low noise regulated output as well as lower input noise than conventional charge pump regulators. High frequency operation (f OSC = 1.5MHz) simplifies output filtering to further reduce conducted noise. To optimize efficiency, the part enters Burst Mode ? operation under light load conditions.
Low operating current (180μA with no load, 10μA in shutdown) and low external parts count (two 1μF flying capacitors and two 10μF bypass capacitors) make the LTC1911 ideally suited for space constrained batterypowered applications. The part is short-circuit and overtemperature protected, and is available in an 8-pin MSOP package.