| 摘要 |
A method (10) and circuit (40) for transition control between step up and step down modes in a charge pump (12). The charge pump (12) starts in an off state (14) and a determination (16) is made if the input voltage is less than or equal to the output voltage. If so, the charge pump (12) is operated (18) in step up mode until it is within regulation. Otherwise, the charge pump (12) is operated (24) in step down mode for at least one cycle. If this brings the charge pump (12) within regulation it is shut down. Otherwise, the charge pump (12) is operated (18) in step up mode until it is within regulation.
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