The LTC3868/-1 operates with a user-adjustable, fixed frequency between 50kHz and 900kHz, and can be synchronized to an external clock from 75kHz to 850kHz using its phase-locked-loop (PLL). The user can select from continuous operation, pulse skipping and low ripple Burst Mode® operation during light loads. These parts also safely start up with a prebiased load by powering up and down in pulse skip mode. The LTC3868/-1’s 2-phase operation reduces input capacitance requirements and its current mode architecture provides easy loop compensation and fast transient response. Both outputs have adjustable soft-start to control the turn-on time, and the output overload protection feature latches off the converter until the input voltage is recycled. The LTC3868/-1 also features a tight ±1.5% reference voltage accuracy over a -40ºC to 85ºC operating temperature range. The LTC3868 is the fully featured part with additional functions beyond the LTC3868-1 including a clock out, phase modulation, two power good outputs and adjustable current limit.
The LTC3868 is offered in a 32-lead 5mm x 5mm QFN package and the LTC3868-1 in 28-pin SSOP or 4mm x 5mm QFN-28 packages.
