| 摘要 |
A regulator is provided. The regulator is a PWM-based switching regulator with soft-start. The regulator starts up with non-synchronously-rectified regulation. A soft-start done signal is asserted after soft-start is finished. In one embodiment, the soft-start done signal is asserted at about 150% of the soft-start time. After the soft-start done signal has been asserted, the regulator changes from non-synchronously-rectified regulation to synchronously-rectified regulation if a pre-determined period of time occurs with no zero-crossing in the inductor current. In one embodiment, the pre-determined period of time is one switching cycle. In some embodiments, the “zero-crossing” of the inductor current is slightly different from zero, such as −0.5 A.
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