The LTC3859EUHF#PBF is a high-performance triple output (buck/ buck/boost) synchronous DC/DC Switching Regulator Controller drives all N-channel power MOSFET stages. Constant frequency current-mode architecture allows a phase-lockable switching frequency of up to 850kHz. It operates from a wide 4.5 to 38V input supply range. When biased from the output of the boost converter or another auxiliary supply, the controller can operate from an input supply as low as 2.5V after start-up. The 55μA no-load quiescent current extends operating runtime in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. It features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator. Independent TRACK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions.
Dual buck plus single boost synchronous controllers
Boost output voltage up to 60V
RSENSE or DCR current sensing
Selectable continuous, pulse-skipping or low ripple burst mode operation at light loads