| 摘要 |
<p>A zero-crossing detection circuit includes a comparator and circuitry. The comparator produces an output signal that is indicative of zero-crossing events in an input Alternating Current (AC) waveform. The circuitry may be configured to feed the comparator with first and second rails voltages, and to progressively increase the rails voltages during time intervals derived from the input AC waveform, so as to feed the comparator with target values of the rails voltages in time-proximity to the zero-crossing events. The circuitry may be configured to compensate for an error in detecting the zero crossing events caused by differences in amplitude of the input AC waveform, by correcting the input AC waveform provided to the comparator. The circuitry may be configured to activate the comparator during time intervals preceding respective anticipated times of the zero-crossing events, and to deactivate the comparator at least once during time periods other than the time intervals.</p> |
