Buck-Boost Regulator Extends Battery Runtime

The LTC35361A synchronous buck-boost dc/dc converter provides up to 1 A at any voltage between 1.8 and 5.5 V from a single Li-Ion/Polymer battery, or 300 mA from a pair of alkaline/NiCd/NiMH batteries. It can be set to deliver any output voltage in that range with +/-1% accuracy, as long as the input voltage from the battery remains within that same range. Because of its buck-boost topology, it can provide up to 25% longer battery runtime than a simple buck regulator in the same application. Peak efficiency is 95%, due, in part to the low conduction losses of its integrated switching MOSFETs. The regulator’s programmable switching frequency can be anywhere between 300 kHz and 2 MHz, and to minimize switching noise, the device provides a continuous transition through all of its operating modes. LTC3536 is comes in either 3mm x 3mm DFN or 10-lead MSOP packaging. Thousand-unit pricing starts at $2.75. LINEAR TECHNOLOGY, Milpitas, CA. (408) 432-1900.