| 摘要 |
A switched mode converter is disclosed that includes mode logic for switching between voltage mode and current mode. The converter includes sensing circuitry for sensing current on the primary side, load current on the secondary side, and converter output voltage. When load current is less than a predetermined value, the converter operates in voltage mode wherein output voltage of the voltage mode controller is used to control the duty cycle of a PWM controller. When load current is greater than a predetermined value, the converter operates in current mode wherein primary current is used to control the PWM controller. Thus during a light load when the converter is voltage controlled there is no need for a minimum load to stabilize the control loop. In current-mode the control loop will have faster transient response and avoid flux imbalance, thereby providing advantages of both voltage and current controlled switched mode converters.
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