LTC3119 buck-boost converter. Source: Linear Technology. User-selectable Burst Mode® operation lowers quiescent current to only 35 µA, improving light load efficiency while extending battery run time. The proprietary four-switch PWM buck-boost topology incorporated in the LTC3119 provides low noise and jitter-free switching through all operating modes, ideal for RF and precision analog 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 400 kHz to 2MHz, which allows for a tradeoff between efficiency and solution size.
Other features include short-circuit protection, thermal overload protection, less than 3 µA shutdown current and a power-good indicator. The device’s combination of tiny externals, wide operating voltage range, compact packaging, plus low quiescent current suits the LTC3119 for RF power supplies, high current pulsed load applications, system backup power supplies and lead-acid battery to 12 V conversion systems.
The LTC3119 is available in thermally enhanced 28-lead 4 mm × 5 mm 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 is from –40° C to 150° C; and MP-grade is 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.
