2A, 1MHz/2MHz Synchronous Step-Up DC/DC Converters

The LTC3539/LTC3539-2 are synchronous, 2A step-up DC/DC converters with output disconnect. Synchronous rectification enables high efficiency in the low profile 2mm × 3mm DFN package. Battery life is extended with a 700mV start-up voltage and operation down to 500mV once started.

A switching frequency of 1MHz (LTC3539) or 2MHz (LTC3539-2) minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. The current mode PWM design is internally compensated, reducing external parts count. The LTC3539/LTC3539-2 feature a pin-enabled automatic Burst Mode operation at light load conditions. Anti-ring circuitry reduces EMI by damping the inductor in discontinuous mode. Additional features include a low shutdown current of under 1μA and thermal overload protection.

The LTC3539/LTC3539-2 are offered in a 2mm × 3mm × 0.75mm DFN package.

Applications

* Medical Instruments

* Portable Bar Code Scanners

* Noise Canceling Headphones

* Portable GPS Navigation

* Handheld PCs

* Delivers 3.3V at 900mA From 2 Alkaline/NiMH Cells* Delivers 5V at 900mA From a Lithium-Polymer Battery* VIN Start-Up Voltage: 700mV* 1.5V to 5.25V VOUT Range* Up to 94% Efficiency* VIN > VOUT Operation* ±1.5% Feedback Voltage Tolerance* 1MHz (LTC3539) or 2MHz (LTC3539-2) Fixed Frequency Operation* Output Disconnect* Selectable Burst Mode® or PWM Operation* 10μA Quiescent Current* Logic Controlled Shutdown: <1μA* Requires Only 6 External Components* Low Profile (2mm × 3mm × 0.75mm) DFN Package