特点
2.7V to 5.5V Input Voltage Range
No Inductors
Li-Ion (3.6V) to 1.5V with 81% Efficiency
Low Noise Constant Frequency Operation
Output Voltages: 1.5V ±4%, 1.2V ±4%
Output Current: 250mA
Shutdown Disconnects Load from V
IN
Low Operating Current: I
Q
= 35μA
Low Shutdown Current: I
SD
<1μA
Oscillator Frequency = 1.5MHz
Soft-Start Limits Inrush Current at Turn-On
Short-Circuit and Overtemperature Protected
Low Profile (1mm) ThinSOT? Package
典型应用
典型应用
描述
The LTC?3250-1.5/LTC3250-1.2 are charge pump stepdown DC/DC converters that produce a 1.5V or 1.2V regulated output from a 2.7V to 5.5V input. The parts use switched capacitor fractional conversion to achieve typical efficiency two times higher than that of a linear regulator. No inductors are required.
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 filtering to further reduce conducted noise. The part also uses Burst Mode? operation to improve efficiency at light loads.
Low operating current (35μA with no load, <1μA in shutdown) and low external parts count (three small ceramic capacitors) make the LTC3250-1.5/LTC3250-1.2 ideally suited for space constrained battery powered applications. The parts are short-circuit and overtemperature protected, and are available in a low profile (1mm) 6-pin ThinSOT? package.
*U.S. Patent #6, 411, 531