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.