Patent ID: 8767419
Filing Date: 2014-07-01
Classification: H02M,Y02B

Abstract:
1. A feedback circuit with feedback impedance modulation comprising: a compare circuit receiving a feedback signal of a power converter to compare the feedback signal with a threshold signal for generating a control signal, wherein the feedback signal is correlated to a load condition of the power converter; a counter coupled to the compare circuit and generating a modulation signal in response to the control signal; and a switching resistor circuit coupled to the counter and a feedback loop of the power converter for modulating a feedback impedance of the power converter in response to the modulation signal; wherein, the feedback impedance is directly modulated from a lower resistance to a higher resistance by the switching resistor circuit and the feedback impedance is increased from the lower resistance directly to the higher resistance when the load condition is reduced from a half/full-load to a no/light-load.