Linear Technology Corp. (LTC, Milpitas, CA) introduced the LTC3730, a three-phase, synchronous, step-down, switching controller with integrated MOSFET drivers dedicated to power Intel's Pentium 4 IMVP-III mobile processors. Housed in a small (5.3mm wide) 36-lead SSOP, the LTC3730 is a single-IC solution capable of delivering up to 60A to the microprocessor core.
The LTC3730's ±5 percent output-current matching simplifies thermal management of the power supply by spreading the heat evenly among its three output stages. The LTC3730 incorporates a patented power-saving technique called Stage Shedding™ to optimize 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 notebook PCs to embedded systems and single-board computers for industrial, instrumentation, telecom and medical systems.
The LTC3730 drives external n-channel MOSFETs in three stages with 120-degree phase separation. The three-phase operation reduces input-ripple current and improves transient response as well as minimizing the requirement for input and output capacitors. The IC operates from 250kHz to 600kHz per phase to achieve optimal frequency for efficiency, ease of thermal design, and use of small inductors and capacitors. The LTC3730's output voltage is adjustable from 0.6V to 1.75V with a five-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.
The LTC3730 is housed in a 5.3mm, 36-lead, SSOP package and priced at $4.35 each in 1,000-piece quantities.
