Power saving modes make the LTC3826/-1 ideal for automotive applications such as navigation systems, where one or both supplies remain active while the engine is off

Linear Technology has released the LTC3826/-1, an ultralow-quiescent-current two-phase dual-output synchronous step-down DC/DC controller. The LTC3826/-1 draws only 30uA when one output is active and only 50uA when both outputs are active, making it ideal for automotive applications, such as navigation systems, where one or both supplies remain active while the engine is off.

With both outputs shut down, the LTC3826/-1 draws a mere 4uA.

The LTC3826/-1’s input supply range of 4 to 36V is wide enough both to protect against high input voltage transients and to continue operation during automotive cold crank.

The LTC3826/-1 features a tight +/-1% reference voltage tolerance over the operating temperature range of -40 to +85C and can provide output voltages from 0.8 up to 10V, suitable for powering audio systems, analogue tuners and CD/DVD players in automobiles.

Each output can deliver up to 20A of current at efficiencies as high as 95%.

The LTC3826/-1’s constant frequency, current mode architecture provides excellent line and load regulation, and its two-phase operation reduces input capacitance requirements.

The LTC3826/-1 smoothly ramps each output voltage during startup using separate adjustable soft-start and tracking pins.

It operates at a selectable frequency between 250 and 550kHz, and can be synchronised to an external clock from 140 to 650kHz using its phased-locked loop (PLL).

In addition, the user can select from Burst Mode operation, pulse skipping and continuous operation at light loads.

There are two versions offered: the LTC3826 is the fully featured part with additional functions that include a clock out, phase modulation, two separate power good signals and a current limit foldback disable capability.

The LTC3826 is offered in 32-lead 5 x 5mm QFN package, whereas the LTC3826-1 is housed in the 28-pin SSOP.