| 摘要 |
<p>A power supply with a digital control circuit generates an output voltage by driving a piezoelectric transducer with an alternating current voltage at a digitally controlled driving frequency. To skip over a spurious frequency, the driving frequency is switched between a first range above the spurious frequency and a second range below the spurious frequency. Within the first and second ranges, the driving frequency is varied in directions that make the output voltage track a target voltage. If the driving frequency arrives at the lower limit of the first range, it jumps to a switchover frequency in the second range. The first range can be used to generate a comparatively low output voltage, and the second range to generate a comparatively high output voltage.</p> |
