
Monolithic 18V synchronous DC-DC converter delivers 95% efficiency
The 2.5V to 18V input voltage range of the LTC3119 extends down to 250mV once started and the output voltage is regulated with inputs above, below or equal to the output and is programmable from 0.8V to 18V. A user-selectable Burst Mode reduces quiescent current to only 35µA, improving light load efficiency while extending battery run time.
The proprietary 4-switch PWM buck-boost topology incorporated in the LTC3119 provides low noise, jitter-free switching through all operating modes for RF and precision analogue applications that are sensitive to power supply noise. The device also includes programmable maximum power point control (MPPC) capability, ensuring maximum power delivery from power sources with high output impedance or photovoltaic cells.
The LTC3119 includes four internal low RDSON N-channel MOSFETs to deliver efficiencies of up to 95%. Burst Mode operation can be disabled, offering low noise continuous switching. External frequency programming or synchronization using an internal PLL enables operation over a wide switching frequency range of 400kHz to 2MHz, which allows for a tradeoff between efficiency and solution size. Other features include short-circuit protection, thermal overload protection, less than 3µA shutdown current, and a power good indicator. The device’s combination of tiny externals, wide operating voltage range, compact packaging, plus low quiescent current makes the LTC3119 well suited for RF power supplies, high current pulsed load applications, system backup power supplies, and lead-acid battery to 12V conversion systems.
The LTC3119 is available in thermally enhanced 28-lead 4mm x 5mm QFN and 28-lead TSSOP packages. E- and I-grade devices are specified over the –40°C to 125°C operating temperature range, H-grade from –40°C to 150°C, and MP-grade from –55°C to 150°C. E-grade pricing starts at $7.15 each in 1,000-piece quantities for both packages. All versions are available from stock.
For more information, visit www.linear.com/product/LTC3119.
