A Simple Control Strategy Using Speedy Transient Response for Multiphase Buck Converter

Abstract. The high performance of recent originating digital processors requires power supply
for transient output, firm voltage regulation and high current. Industry has taken up interleaved
multiphase synchronous buck converters for meeting such demands. Application of the voltage
mode (ripple) hysteretic strategy to multiphase Voltage Regulator Units (VRU) would help
satisfying many of the upcoming digital processors and IC’s powering demands. This arises
from the use of the various advantages that can be obtained from this technique. This current
division method is known for several benefits it provides: easy accessibility in application to all
control methods, with freedom from the prime control technique in voltage regulation loop,
absence of any necessity for current reference, better accuracy in current division of equal
magnitude at almost every load conditions in standstill and transients. As against this, there are
several challenges that involve distribution of multiple control signals, current sharing and
sensitivity to noise, high speed comparators, hysteretic band accuracy and stable at large load
transients. In addition, application of the current division technique presented was made to a
multiphase voltage mode ripple controlled Buck Converter that produced a novel and easy
control strategy having minimum output voltage ripples and speedy transient output.