A Resolution Improving MethodofDigital PWM usingPulse CompositeTechnique

Inrecent years, digitization ofallcontrol partsinswitching powersupplies including PWM generators isprogressing fordemands suchasintelligent performances andcommonuseofhardware, etc.Then, aproblem isintheresolution ofdigital PWM generators forimproving control performances. Since thedigital PWM generator isconstituted usingacounter, acarrier waveturnsintoastairs wave,andstepamplitudes isdecided withaclock cycle. Whentheclock cycle isfixed, theresolution becomes lowastheswitching frequency becomes high.Consequently, theaccuracy ofoutput voltage becomes bad.Inthis paper, amethod forremarkably improving theresolution ofthedigital PWM generator using thepulse composite technique is proposed. Themethodisrealizable bysomeparts andeasycomputation, andisapplied tothedigital PWM generator built-in DSP.Theusefulness andpracticality areverified byexperiments.