Features

• Regulated Output with Input Voltages Above, Below or Equal to the Output
• 1.8V to 5.5V Input and 1.8V to 5.25V Output Range
• 250mA Continuous Output Current from 1.8V VIN
• 600mA Continuous/1A Peak Output Current from Li-Ion
• Single Inductor
• Synchronous Rectification: Up to 96% Effi ciency
• Programmable Automatic Burst Mode® Operation
• Output Disconnect in Shutdown
• Pin Compatible with the LTC3440
• Programmable Frequency from 300kHz to 2MHz
• <1µA Shutdown Current
• Small Thermally Enhanced 10-Lead (3mm × 3mm) DFN and 10-Lead MS Packages

Typical Application

Description

The LTC3530 is a wide VIN range, highly efficient, fixed frequency, buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for single lithium-ion, two-cell alkaline or NiMH applications where the output voltage is within the battery voltage range.

The LTC3530 is pin compatible with the LTC3440 buckboost DC/DC converter but adds programmable automatic Burst Mode operation and extends the VIN/VOUT range to 1.8V. Switching frequencies up to 2MHz are programmed with an external resistor. Automatic Burst Mode operation allows the user to program the load current threshold for Burst Mode operation using a single resistor from the BURST pin to GND.

Other features include 1µA shutdown, short circuit protection, programmable soft-start control, current limit and thermal shutdown. The LTC3530 is available in a thermally enhanced 10-lead (3mm × 3mm) DFN or MSOP package.