| 摘要 |
A DC-to-DC converter comprises an error amplifier, a comparator, a PWM controller, a power switch unit, and a control signal monitoring circuit. The PWM controller receives a comparison signal from the comparator and generates a digital control signal that controls the power switch unit such that the DC-to-DC converter supplies a regulated voltage onto a load. The control signal monitoring circuit monitors the digital control signal and detects either a heavy load or a light load condition based on characteristics of the digital control signal. Under the light load condition, the monitoring circuit generates a first enabling signal such that the DC-to-DC controller operates in a power-save mode. Under the heavy load condition, the monitoring circuit generates a second enabling signal such that the DC-to-DC controller operates in a normal operation mode. The DC-to-DC converter consumes substantially less power in the power-save mode than in the normal operation mode.
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