Design of a switching frequency adaptive slope compensation circuit for frequency synchronous DC–DC converters

The inductor value of the frequency synchronous DC–DC converter is related to the operating switching frequency. In order to optimize the performance of stability, transient response and load capability, this paper presents a switching frequency adaptive slope compensation circuit. The circuit adjusts the slope compensation by automatic operation according to the synchronized switching frequency to avoid excessive compensation. The proposed circuit has been implemented in a high voltage buck DC–DC converter with 0.6 μm CDMOS process. The test results indicate that fast transient response and load capability are realized and the stability is achieved without sub-harmonic oscillation in the whole synchronous frequency range.

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► A frequency adaptive slope compensation circuit is proposed.
► The slope compensation adjusts with the synchronized switching frequency.
► Avoids excessive compensation and sub-harmonic oscillation.
► The circuit is implemented and verified in a frequency synchronous DC–DC converter.
► Transient response and load capability have well performance in the frequency range.