15V, 1.5A Synchronous Buck-Boost DC/DC Converter
FEATURES
■ Regulated Output with VIN Above, Below or Equal to VOUT
■ 2.5V to 15V Input and Output Voltage Range
■ 1.5A Continuous Output Current: VIN ≥ 5V, VOUT = 5V, PWM Mode
■ Single Inductor
■ Accurate RUN Threshold
■ Up to 95% Efficiency
■ 800kHz Switching Frequency, Synchronizable Between 600kHz and 1.5MHz
■ 49μA No-Load Quiescent Current in Burst Mode® Operation
■ Output Disconnect in Shutdown
■ Shutdown Current < 1μA
■ Internal Soft-Start
■ Small, Thermally Enhanced 14-Lead (3mm × 4mm × 0.75mm) DFN and 16-Lead MSOP Packages

APPLICATIONS
■ 3.3V or 5V from 1, 2 or 3 Li-Ion, Multiple-Cell Alkaline/NiMH Batteries
■ RF Transmitters
■ Military, Industrial Power Systems

DESCRIPTION
The LTC3111 is a fixed frequency, synchronous buck-boost DC/DC converter with an extended input and output range. The unique 4-switch, single inductor architecture provides low noise and seamless operation from input voltages above, below or equal to the output voltage.
With an input and output range of 2.5V to 15V, the LTC3111 is well suited for a wide variety of single or multiple-cell batteries, back-up capacitor or wall adapter source applications. Low Rds(ON) internal N-channel MOSFET switches and selectable PWM or Burst Mode operation produce high efficiency over a wide range of operating conditions.
An accurate RUN pin allows the user to program the turn-on threshold voltage of the converter. Other features include: short-circuit protection, internal soft-start and thermal shutdown.
The LTC3111 is offered in both thermally enhanced 14-lead (3mm x4mm x 0.75mm) DFN and 16-lead MSOP packages.