40VIN/OUT, 1A synchronous buck-boost DC/DC converter

May 12, 2014 // By Paul Buckley
LTC3114-1 is a synchronous, current-mode buck-boost converter that delivers up to 1A of continuous output current from a wide range of power sources, including single-cell Li-Ion, 24V/28V industrial rails and 40V automotive inputs, and that offers a 2.7V to 40V input and output range.

The device’s 2.2V to 40V input and 2.7V to 40V output range provides a regulated output with inputs above, below or equal to the regulated output, maximising power source flexibility and extending battery run time over step-down only solutions. Low noise buck-boost topology provides a continuous jitter-free transition between buck and boost modes, making it sutiable for RF and other noise-sensitive applications.

Selectable Automatic Burst Mode operation lowers quiescent current to 30 µA, improving light load efficiency and further extending battery run time. The LTC3114-1 uses a constant 1.2 MHz switching frequency and features pin-programmable average output current and current monitor. Proprietary buck-boost PWM circuitry ensures low noise and high efficiency while minimising the size of external components. The combination of tiny externals and a 3 x 5 mm DFN or TSSOP-16E package provides a compact solution footprint.

The LTC3114-1 incorporates four internal low R DS(ON) N-channel MOSFETs to deliver efficiencies of up to 96%. Automatic Burst Mode operation lowers quiescent current to 30 µA, improving light load efficiency and extending battery run time. For noise-sensitive applications, Burst Mode operation can be disabled. Furthermore, current-mode control improves line and load transient responses while keeping compensation simple. Additional features include internal soft-start and inrush current limit, undervoltage lockout, thermal overload protection, short-circuit protection and output disconnect.

LTC3114EDHC-1 in a 16-lead 3 x 5 mm DFN package and LTC3114EFE-1 in a thermally enhanced 16-lead TSSOP package have pricing starting at $3.95 (1000). Industrial temperature range and high-reliability versions are available.

Linear Technology; www.linear.com/product/LTC3114