LTC3250-1.5

` 3.1V to 5.5V Input Voltage Range
` No Inductors
` Li-Ion (3.6V) to 1.5V with 81% Efficiency
` Low Noise Constant Frequency Operation
` Output Voltage: 1.5V ±4%
` Output Current: 250A
` Shutdown Disconnects Load from V<sub>IN</sub>
` Low Operating Current: I_Q = 35A
` Low Shutdown Current: I<sub>SD</sub> < 1A
` Oscillator Frequency = 1.5MHz
` Soft-Start Limits Inrush Current at Turn-On
` Short-Circuit and Overtemperature Protected
` Low Profile (1mm) ThinSOT^TM Package

·Handheld Computers
· Cellular Phones
· Digital Cameras
· Handheld Medical Instruments
· Low Power DSP Supplies

V_IN to GND ...................................................... 0.3V to 6V
SHDN to GND .................................... 0.3V to (V_IN + 0.3V)
I_OUT (Note 2)........................................................... 350mA
Operating Temperature Range (Note 3) .. 40°C to 85°C
Storage Temperature Range ................ 65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................... 300°C

The LTC^®3250-1.5 is a charge pump step-down DC/DC converter that produces a 1.5V regulated output from a 3.1V to 5.5V input. The part uses switched capacitor fractional conversion to achieve a typical efficiency increase of 50% over that of a linear regulator. No inductors are required.

A unique constant frequency architecture of LTC3250-1.5 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 (35mA with no load, <1A inshutdown) and low external parts count (three smallceramic capacitors) make the LTC3250-1.5 ideally suited for space constrained battery powered applications. The part is short-circuit and overtemperature protected, and is available in a low profile (1mm) 6-pin ThinSOT package.