Featuring a constant-frequency current mode architecture, the LTC3853 allows a selectable fixed or synchronised frequency from 250-750kHz. The controller operates the three stages 120° out-of-phase, minimising power loss and supply noise. By measuring the voltage drop across the output inductor (DCR) or using an optional sense resistor, output current sensing is accomplished. Heat dissipation from 1.1Ω on-chip MOSFET gate drivers, which are featured within the controller, is limited by current foldback. Selectable Burst Mode operation, pulse skipping or continuous inductor current modes are user controlled to optimise light load efficiency.
With up to 98% duty cycle, the LTC3853 has a low dropout voltage, making it suitable for extending run times in battery-powered applications. Available in a thermally enhanced 6x6mm QFN-40 package, the controller is priced at $4.24.