Linear Technology's latest dual output synchronous step-down DC/DC controller offers multiphase operation, differential output voltage sensing and high frequency operation.

Working with external power train devices such as power blocks and DrMOS, as well as discrete N-channel mosfets, up to 12 phases can be paralleled and clocked out-of-phase to minimise input and output filtering for very high current requirements (up to 300A).

The LTC3861’s current sharing loop is designed for accurate current sharing between phases across multiple ICs, both DC and during a load transient. The device’s voltage mode control architecture allows for selectable fixed operating frequency from 250kHz to 2.25MHz or it can be synchronized over the same range with its phased-lock loop (PLL).

The differential amplifier provides true remote output voltage sensing of both VOUT and ground terminals, enabling high accuracy regulation.

The device operates with a VCC voltage ranging from 3V to 5.5V, a VIN voltage (drain voltage for the high-side mosfet) from 3V to 24V and it produces output voltages from 0.6V to 5V.

The output current is sensed by monitoring the voltage drop across the output inductor (DCR) for maximum efficiency or using a sense resistor. Its adjustable current limit can be configured for very low sense voltages (up to 50mV) to minimize power loss.

The LTC3861 is housed in a 36-lead 5mm x 6mm QFN package. 

www.linear.com/product/LTC3861