Synchronous buck-boost DC/DC converters consume only 1.6µA of quiescent current

New from Linear Technology the LTC3130 and LTC3130-1 are synchronous current mode buck-boost converters that are able to deliver up to 600mA of continuous output current from a wide variety of input sources, including single- or multiple-cell batteries as well as solar panels and supercapacitors.

The converter’s 2.4V to 25V input voltage range and 1V to 25V output range (the LTC3130 is adjustable) are able to provide a regulated output with inputs above, below or equal to the output.

A user selectable Burst Mode operation lowers quiescent current to only 1.6µA (1.2µA at no load) improving light load efficiency and extending battery run time. The proprietary buck-boost topology incorporated in the LTC3130/-1 provides low noise, jitter-free switching through all operating modes and, according to Linear, is suitable for RF and precision analogue applications that are sensitive to power supply noise.

The device also includes a programmable maximum power point control (MPPC) capability, ensuring maximum power delivery from non-ideal power sources such as photovoltaic cells.

The LTC3130-1 shares all of the features of the LTC3130, but offers four user-selectable fixed output voltages: 1.8V, 3.3V, 5V and 12V, eliminating the resistor divider required for the adjustable output version.

The LTC3130/-1 includes four internal low RDSON N-channel MOSFETs to deliver efficiencies of up to 95%. Due to its low quiescent current, converter start-up can be achieved from sources as low as 7.5µW, making the LTC3130/3130-1 ideal for applications powered by weak sources, including thin film solar cells. Alternatively, Burst Mode operation can be disabled, offering low noise continuous switching.

The LTC3130/-1’s constant 1.2MHz switching frequency ensures low noise and high efficiency, while minimising the size of the external components. Built-in loop compensation and soft-start reduce external parts count and simplify design.

Other features include a power good indicator, pin-selectable current limit, an accurate RUN pin threshold, an external VCC input and thermal shutdown. The device’s combination of tiny externals, wide operating voltage range, compact packaging, plus ultralow quiescent current makes the LTC3130/-1 well suited for always-on applications in which extended battery run time is of primary importance, such as long life battery-powered instruments, portable military radios, low power sensors and solar panel post-regulator/charger circuits.

The LTC3130 and LTC3130-1 are available in thermally enhanced 20-lead 3mm x 4mm QFN and 16-lead MSOP packages. E- and I-grade devices are specified over the –40°C to 125°C operating temperature range.

Neil Tyler