200mA Buck-Boost Synchronous DC/DC Converters

The LTC3531/LTC3531-3.3/LTC3531-3 are synchronous buck-boost DC/DC converters that operate from input voltages above, below or equal to the output voltage. The topology incorporated in the ICs provides a continuous transfer through all operating modes, making the product ideal for single cell Li-Ion and multicell alkaline or nickel applications. The converters operate in Burst Mode, minimizing solution footprint and component count as well as providing high conversion efficiency over a wide range of load currents.

The devices include two 0.5Ω N-channel MOSFET switches and two P-channel switches (0.5Ω, 0.8Ω). Quiescent current is typically 16μA, making the parts ideal for battery power applications. Other features include a <1μA shutdown current, current limiting, thermal shutdown and output disconnect. The parts are offered in a 6-pin ThinSOT™ package for fixed voltage versions or a 3mm × 3mm DFN package for fixed and adjustable versions.

Applications

* Handheld Instruments

* MP3 Players

* Handheld computers

* PDA/GPS

* Regulated Output with Input Above, Below or Equal to the Output

* Single Inductor

* Up to 90% Efficiency

* VIN Range: 1.8V to 5.5V

* 200mA at 3.3VOUT from 3.6V Input

* 125mA at 3VOUT from 2.5V Input

* Fixed VOUT Versions (TSOT, DFN): 3.3V, 3V

* Adjustable VOUT Version (DFN): 2V to 5V

* Burst Mode® Operation, No External Compensation

* Ultra Low Quiescent Current: 16μA, Shutdown Current <1μA

* Only 3 External Components Required

(Fixed Voltage Versions)

* Short-Circuit Protection

* Output Disconnect in Shutdown

* Available in 6-Pin ThinSOT and 3mm × 3mm DFN Packages