Analog Devices LTC3539 Product Info

• Delivers 3.3V at 900mA From 2 Alkaline/NiMH Cells
• Delivers 5V at 900mA From a Lithium-Polymer Battery
• V_IN Start-Up Voltage: 700mV
• 1.5V to 5.25V V_OUT Range
• Up to 94% Efficiency
• V_IN > V_OUT 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

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