The LTC3859A is a high performance triple output (buck/buck/boost) synchronous DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Constant frequency current mode architecture allows a phase-lockable switching frequency of up to 850kHz. The LTC3859A operates from a wide 4.5V to 38V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC3859A 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. The LTC3859A features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.Compared to the LTC3859, the LTC3859A's boost controller has improved performance in Burst Mode operation when the input voltage is higher than the regulated output voltage.Quiescent Current (Burst Mode)NotesLTC3859AL28μA-One channel on, Buck38μA-All three channels onInternal clamp on the INTVCC pinLTC3859A55μA-One channel on, Buck80μA-All three channels onInternal clamp on the INTVCC pin. For new designs, we recommend LTC3859ALLTC385955μA-One channel on, Buck80μA-All three channels onFor new designs, we recommend LTC3859ALApplicationsAutomotive Always-On and Start-Stop SystemsBattery Operated Digital DevicesDistributed DC Power SystemsMultioutput Buck-Boost Applications