| 摘要 |
<p>A switched mode power supply, comprising: a switching device (110), the switched mode power supply being operable to convert an input voltage (Vin) to an output voltage (Vout) by switching the switching device; a feedback circuit (140) operable to generate a feedback signal based on at least one of the output voltage and an output current of the switched mode power supply; a current limiting circuit (160, 170') operable to determine a current in the switched mode power supply and generate an excess current control signal when the current exceeds a current threshold; and a controller (150). The controller is arranged to receive the feedback signal and the excess current control signal, and operable to control the switching device (110): in a first operational mode when the current determined by the current limiting circuit is below the current threshold, to regulate one of the output voltage and the output current based on the feedback signal; and in a second operational mode when the current determined by the current limiting circuit exceeds the current threshold, to reduce the current in the switched mode power supply on the basis of the excess current control signal. The power supply further comprises an overload detector (180), which is arranged to receive the feedback signal and operable to: determine whether the feedback signal is outside a predetermined range; if the feedback signal is outside the predetermined range, determine that the switched mode power supply is in an overload state; and when an overload state is determined, perform control to place the switched mode power supply in a non-operational state.</p> |
