Dual dc/dc step-down controller features integrated tracking, PLL

Linear Technology Corporation has introduced the LTC3828, a dual step-down synchronous switching controller used to convert a 4.5 V to 28 V input voltage to two regulated output voltages, adjustable from 0.8 V to 99% of the value of the input voltage.

Available in a 28-lead SSOP and 5 mm x 5 mm QFN packages, the controller features integrated tracking for sequencing multiple voltage rails, phase-locked loop (PLL) for precision synchronization, and PolyPhase operation for reducing input capacitance. Multiple LTC3828s or other dc/dc converters can be daisy-chained together to provide tracking for more than two voltages while operating at three, four or six phases. The device has a constant 550 kHz frequency current mode architecture and can be locked to a 260 kHz to 550 kHz clock to reduce EMI at sensitive frequencies. Its wide operating voltage and integrated functions enable the design of compact multiple output power supplies in automotive electronics among other applications.