Buck-boost converter does 2.7 to 40V input/output, provides bump-free transitions
Bill Schweber, EE Times -- EDN, February 2, 2012
Targeting the challenge of supporting a wide range of input voltages and delivering a wide range of output voltages, the LTC3115-1 dc/dc buck-boost converter from Linear Technology Corp delivers as much as 2A continuous current. It handles power sources spanning a single-cell lithium-ion source, to 24/28V industrial supplies, and to 40V automotive sources, and it provides a regulated output from inputs that can be above, equal to, or below the desired output value. It also provides jitter-free transitions between buck and boost modes.
The low-noise, high-efficiency LTC3115-1
has an advanced PWM and low-noise
switching algorithm and circuit. It includes
four MOSFETs that provide as much as 95%
efficiency, with a burst mode of operation
that drops quiescent current to 50 μA for better
light-load efficiency and longer runtime.You can selectively turn off the burst mode for extremely noise-sensitive applications. The device has an operating envelope of 1A output current for input voltages of 3.6V or more and output voltages of 5V and an envelope of 2A output current in step-down operation for input voltages of 6V or more. Other attributes include internal soft-start operation, 3-μA supply current in shutdown mode, and programmable input-undervoltage lockout.
The LTC3115-1 is available in a 4×5×0.75-mm DFN package and in a thermally enhanced 20-lead TSSOP for $5.35 and $5.55 (1000), respectively; industrial-grade versions operating at −40 to +125°C are also available.
Linear Technology Corp
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