DC/DC controller

Linear Technology has introduced the LTC3730, a three-phase synchronous step-down switching controller with integrated MOSFET drivers dedicated to power the Pentium 4 IMVP-III mobile processors.

The device is a single-IC capable of delivering up to 60 A to the microprocessor core. Its precision ±5% output current matching simplifies thermal management of the power supply by spreading the heat evenly among its three output stages.

The device incorporates a power-saving technique called stage shedding to optimise efficiency and improve battery life at light loads by eliminating the gate charging losses and switching losses of two of its output stages.

Applications vary from high-end notebooks to embedded systems and single-board computers for industrial, instrumentation, telecom and medical systems.

The device drives external n-channel MOSFETs in three stages with 120° phase separation. The three-phase operation reduces input ripple current and improves transient response as well as minimising the requirement for input and output capacitors.

The IC operates from 250 to 600 kHz per phase to achieve optimal frequency for efficiency, ease of thermal design and use of small inductors and capacitors.

The output voltage is adjustable from 0.6 to 1.75 V with a 5 bit VID interface.

To protect the load and MOSFETs, the LTC3730 is equipped with short-circuit and overload protection as well as soft-start to protect the system from inrush current.