Method for balancing current

Abstract

A method for method for inhibiting thermal run-away in a multi-phase power converter at varying load transition rates. A multi-phase power converter having an on-time is provided and the frequency of the multi-phase power converter is adjusted so that a load step period and the on time of the multi-phase power converter are in a temporal relationship. Alternatively, a load step rate is inhibited from locking onto a phase current of the multi-phase power converter by suspending an oscillator signal. In accordance with another alternative, a load step rate is inhibited from locking onto a phase current of the multi-phase power converter by suspending an oscillator signal and dithering an input signal to the oscillator.

1 : A method for balancing current in a multi-phase power converter at varying load transition rates, comprising:
 providing the multi-phase power converter having an on-time; and   adjusting the frequency of the multi-phase power converter so that a load step period and the on-time of the multi-phase power converter are in a temporal relationship.   
     
     
         2 : The method of  claim 1 , wherein the temporal relationship is one of coincident, similar, or the same. 
     
     
         3 : The method of  claim 1 , wherein providing the multi-phase power converter includes:
 providing an error amplifier having an output;   providing an oscillator having an output;   coupling the output of the error amplifier to a first input of a pulse width modulator;   coupling the output of the oscillator to a second input of the pulse width modulator; and   providing a first power stage having an input coupled to an output of the pulse width modulator.   
     
     
         4 : The method of  claim 3 , further including:
 coupling a second power stage having an input to another output of the pulse width modulator;   coupling a first inductor between the output of the first power stage and an output node;   coupling a second inductor between the output of the second power stage and the output node; and   coupling the output node to an input of the error amplifier.   
     
     
         5 : The method of  claim 1 , wherein the temporal relationship between the on-time of the multi-phase power converter and the load step is a coincidental relationship. 
     
     
         6 : The method of  claim 1 , wherein the multi-phase power converter is a 4-phase power converter. 
     
     
         7 : The method of  claim 1 , wherein the multi-phase power converter is one of a 2-phase power converter or a 3-phase power converter. 
     
     
         8 : The method of  claim 1 ., further including coupling a dither circuit to the Multi-phase power converter. 
     
     
         9 : The method of  claim 1 , wherein adjusting the on-time of the multi-phase power converter includes dithering an oscillator signal. 
     
     
         10 : The method of  claim 1 , Wherein adjusting the on-time of the multi-phase power converter includes one of suspending an oscillator signal or phase Shifting the oscillator signal. 
     
     
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