GENERAL DESCRIPTION
The ADP3421 is a hysteretic dc-dc buck converter controller with two auxiliary linear regulator controllers. The ADP3421 provides a total power conversion control solution for a microprocessor by delivering the core, I/O, and clock voltages. The optimized low-voltage design is powered from the 3.3 V system supply and draws only 10 µA maximum in shutdown. The main output voltage is set by a 5-bit VID code. To accommodate the transition time required by the newest processors for on-thefly VID changes, the ADP3421 features high-speed operation to allow a minimized inductor size that results in the fastest change of current to the output.

FEATURES
   Meets Intel® Mobile Voltage Positioning Requirements
   Lowest Processor Dissipation for Longest Battery Life
   Best Transient Containment
   Minimum Number of Output Capacitors
   System Power Management Compliant
   Fast, Smooth Output Transition During VID Code
      Change
   Programmable Current Limit
   Power Good
   Integrated LDO Controllers for Clock and I/O Supplies
   Programmable UVLO
   Soft Start with Restart Lock-In

APPLICATIONS
   Geyserville-Enabled Core DC-DC Converters
   Fixed Voltage Mobile CPU Core DC-DC Converters
   Notebook/Laptop Power Supplies
   Programmable Output Power Supplies