Linear Technology LTC3113 synchronous buck-boost converter

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Linear Technology has released the LTC3113, a synchronous buck-boost converter that delivers 3 A of output from a nominal 3.3 V power source, Li-Ion/polymer battery or up to 1 A from dual cell alkaline/NiCad/NiMH batteries.

The device’s 1.8 to 5.5 V input range and 1.8 to 5.5 V output range provides a regulated output from an input voltage above, below or equal to the output. It is also a regulator to maximise the energy available from a two supercapacitor stack.

The proprietary buck-boost topology delivers a continuous transition through all operating modes, making it suitable for applications that must maintain a constant, low-noise output voltage even as the input voltage declines below the output.

In many cases, this can add up to 25% more battery run time compared with a buck regulator. The constant switching frequency is user programmable from 300 kHz up to 2 MHz to optimise the balance between efficiency and external component size.

The device includes two N-channel MOSFETs and two P-channel MOSFETs (R _DS(ON) of 29 and 40 mΩ) to deliver efficiencies of up to 96%. User-selectable burst mode operation lowers quiescent current to 40 µA, improving light load efficiency and further extending battery run time. For noise-sensitive applications, the burst mode operation can be disabled.

Other features include soft start, current limiting, thermal shutdown and output disconnect.