Microcontroller-Based Peak Current Mode Control Using Digital Slope Compensation

Michael Hallworth, Seyed Ali Shirsavar
2012 IEEE transactions on power electronics  
Microcontroller based peak current mode control of a Buck converter is investigated. The new solution uses a discrete time controller with digital slope compensation. This is implemented using only a single-chip microcontroller to achieve desirable cycle-by-cycle peak current limiting. The digital controller is implemented as a two pole, two zero linear difference equation designed using a continuous time model of the Buck converter and a discrete time transform. Subharmonic oscillations are
more » ... oscillations are removed with digital slope compensation using a discrete staircase ramp. A 16W hardware implementation directly compares analog and digital control. Frequency response measurements are taken and it is shown that the crossover frequency and expected phase margin of the digital control system match that of its analog counterpart. Index Terms Digital peak current mode control, DC-DC switch mode power supplies, discrete controller, digital slope compensation. . This paper has been submitted solely to IEEE Transactions on Power Electronics and has not been presented at a conference. NOMENCLATURE C O Output filter capacitor.
doi:10.1109/tpel.2011.2182210 fatcat:vhn6mfhcdba4xkpbaho5cmsrja