The LTC3836 is a 2-phase dual output synchronous step-down switching regulator controller with tracking that drives external N-channel power MOSFETs using few external components. The constant-frequency current mode architecture with MOSFET VDS sensing eliminates the need for sense resistors and improves efficiency. The power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out-of-phase. Pulse-skipping operation provides high efficiency at light loads. The 97% duty cycle capability provides low dropout operation, extending operating time in battery-powered systems. The operating frequency is selectable from 300kHz to 750kHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications, the LTC3836 operating frequency can be externally synchronized from 250kHz to 850kHz. The LTC3836 features an internal 1ms soft-start that can be extended with an external capacitor. A tracking input allows the second output to track the first during start-up. The LTC3836 is available in the tiny thermally enhanced (4mm × 5mm) QFN and 28-lead narrow SSOP packages.
