3PHASEPWM

3-Phase Synchronous PWM Controller IC Provides an Integrated Solution for Intel VRM 9.0 Design Guidelines Odile Ronat International Rectifier The fundamental reason for the rapid change and growth in information technology power requirements is the increase in volume of data processed, stored, transmitted, and displayed. As a result, power requirements have grown very rapidly. To control the increase in power dissipation, operating voltages have been reduced. Power scales as the square of the voltage: cut the voltage in half, and the power dissipation is reduced to one fourth. As circuit output voltages approach the one-volt mark, operating currents are increasing exponentially. Today, feeding this much “ultraclean” current at these low voltages with tremendous transient response capability is the key technology driver of power management for IT. CPUs used in servers, advance desktop computers and motherboards such as the Intel Pentium™ 4 or Xeon™ or AMD K7™ typically require currents up to 60A at output voltages around 1V, with transient response in the order of 50A/us. Designers prefer a multiphase DCDC converter topology to address the higher current requirements response problem, and faster transient This article will discuss the specific requirements for DC-DC converters required to power today’s GHz class CPUs, the benefits of the multiphase topology, and an example of implementation of Intel VRM 9.0 using an integrated 3-phase synchronous PWM controller IC. An Overvie...