We explain the mechanism that causes "intermittent" instability and chaos in a current-mode controlled switching converter. The circuit model used to study the phenomenon incorporates a coupling process through which a spurious signal is coupled to the current sensing and ramp compensation circuitry, resulting in a modulation of the compensation slope which causes the system to become unstable intermittently. We describe a way to find the parameter boundaries where intermittent chaotic operation emerges.
['Siu Chung Wong', 'Chi K. Michael Tse', 'K. C. Tam']
Spurious modulation on current-mode controlled DC/DC converters: an explanation for intermittent chaotic operation