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AssigneeVirginia Tech Intellectual Properties, Inc.
InventorsKuang-Yao Cheng, Feng Yu, Paolo Mattavelli, Fred C. Lee
Estimating the term…
Stabilization of a switching voltage regulator employing V2 control against ripple oscillation instability when the equivalent series resistance (ESR) of an output capacitor is small is provided by providing both an external ramp and an internal ramp (only the latter of which requires an approximation of inductor current) in the control feedback path, preferably including both inner and outer feedback loops. Approximation of inductor current using such an arrangement is non-critical and may be estimated based on power input voltage. Drift of a circuit providing such an inductor current estimation is preferably avoided by adjusting control duty cycle or slew rate of the positive-going ramp portion of the estimated inductor current triangular waveform.
A switched power converter comprising
A digital triangular waveform generator which closely matches durations of rising and falling portions of a triangular waveform to a duty cycle of a control signal, said digital triangular waveform generator comprising a multiplexer and a low pass filter, said multiplexer providing a first input parameter value or a second input parameter value to said low pass filter in synchronism with a periodic control signal, wherein a DC level of said triangular waveform is adjusted by comparison of a value of said triangular waveform at a detected minimum of said triangular waveform with a reference value to compensate for drift by adjustment of a duty cycle or a slew rate of portions of said triangular waveform at a frequency of said control signal.
Dependencies are inferred from the claim text.