| 摘要 |
A control circuit (210) operable to control the switching of switching elements in a switched mode power supply (200). The control circuit (210) comprises a switching control signal generator (220) operable to generate control signals for switching the switching elements such that the switched mode power supply converts an input voltage (Vin) to an output voltage (Vout). The control circuit (210) further comprises an operation mode setting module (260) which is operable to receive a signal (I) indicative of a current flowing to a load that is connected to an output of the switched mode power supply, and operable to cause the switching control signal generator (220) to generate the control signals so as to operate the switched mode power supply (200) in a continuous conduction mode or a pulse skipping mode in dependence upon the current. In the pulse skipping mode, the switching elements are turned OFF for at least one switching period of the switched mode power supply (200) but the switched mode power supply continues to supply power to the load. The operation mode setting module (260) is operable to monitor the signal (I) to determine whether the current exceeds a threshold, and is operable to control the switching control signal generator (220) to generate the control signals such that, when the current exceeds the threshold, the switched mode power supply (200) operates in the continuous conduction mode and, upon determining that the current has fallen to or below the threshold, operation of the switched mode power supply (200) is changed from the continuous conduction mode to the pulse skipping mode so that the pulse skipping mode is entered from the continuous conduction mode. |
