The LTC3738 is a 3-phase synchronous step-down switching regulator controller that drives all N-channel external power MOSFET stages in a phase-lockable, fixed frequency architecture. The 3-phase technique effectively triples the fundamental frequency, improving transient response while operating each controller at an optimal frequency for efficiency and ease of thermal design. Light load efficiency is optimized by using a choice of output Stage Shedding or Pulse Skip mode technology.The LTC3738 also allows users to program load slope via a resistor for AVP control. Both external and internal thermal sensing are available from the on-chip thermal detector and comparator.A differential amplifier provides sensing of both the high and low sides of the output voltage.Soft-start and a defeatable, timed short-circuit shutdown protect the MOSFETs and the load. A foldback current circuit also provides protection for the external MOSFETs under short-circuit or overload conditions. An all- "1" VID detector turns off the regulator after a 1µs timeout.ApplicationsHigh Performance Notebook ComputersServers, Desktop Computers and Workstations