SYSTEM AND METHOD PROVIDING OVER CURRENT PROTECTION BASED ON DUTY CYCLE INFORMATION FOR POWER CONVERTER
First Claim
1. A system controller for protecting a power converter, the system controller comprising:
- a signal generator configured to generate a threshold signal;
a comparator configured to receive the threshold signal and a current sensing signal and generate a comparison signal based on at least information associated with the threshold signal and the current sensing signal, the current sensing signal indicating a magnitude of a primary current flowing through a primary winding of a power converter; and
a modulation and drive component coupled to the signal generator and configured to receive at least the comparison signal, generate a drive signal based on at least information associated with the comparison signal, and output the drive signal to a switch in order to affect the primary current, the drive signal being associated with one or more first switching periods and a second switching period following the one or more first switching periods, the one or more first switching periods corresponding to one or more first duty cycles;
wherein the signal generator is further configured to, for the second switching period,determine a first threshold signal value based on at least information associated with the one or more first duty cycles; and
generate the threshold signal equal to the determined first threshold signal value, the threshold signal being constant in magnitude as a function of time for the second switching period.
1 Assignment
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Accused Products
Abstract
System and method for protecting a power converter. An example system controller for protecting a power converter includes a signal generator, a comparator, and a modulation and drive component. The signal generator is configured to generate a threshold signal. The comparator is configured to receive the threshold signal and a current sensing signal and generate a comparison signal based on at least information associated with the threshold signal and the current sensing signal, the current sensing signal indicating a magnitude of a primary current flowing through a primary winding of a power converter. The modulation and drive component is coupled to the signal generator.
10 Citations
66 Claims
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1. A system controller for protecting a power converter, the system controller comprising:
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a signal generator configured to generate a threshold signal; a comparator configured to receive the threshold signal and a current sensing signal and generate a comparison signal based on at least information associated with the threshold signal and the current sensing signal, the current sensing signal indicating a magnitude of a primary current flowing through a primary winding of a power converter; and a modulation and drive component coupled to the signal generator and configured to receive at least the comparison signal, generate a drive signal based on at least information associated with the comparison signal, and output the drive signal to a switch in order to affect the primary current, the drive signal being associated with one or more first switching periods and a second switching period following the one or more first switching periods, the one or more first switching periods corresponding to one or more first duty cycles; wherein the signal generator is further configured to, for the second switching period, determine a first threshold signal value based on at least information associated with the one or more first duty cycles; and generate the threshold signal equal to the determined first threshold signal value, the threshold signal being constant in magnitude as a function of time for the second switching period. - View Dependent Claims (2, 3, 4)
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5-25. -25. (canceled)
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26-61. -61. (canceled)
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62. A method for protecting a power converter, the method comprising:
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generating a threshold signal; receiving the threshold signal and a current sensing signal, the current sensing signal indicating a magnitude of a primary current flowing through a primary winding of a power converter; generating a comparison signal based on at least information associated with the threshold signal and the current sensing signal; receiving at least the comparison signal; generating a drive signal based on at least information associated with the comparison signal, the drive signal being associated with one or more first switching periods and a second switching period following the one or more first switching periods, the one or more first switching periods corresponding to one or more duty cycles; and outputting the drive signal to a switch in order to affect the primary current; wherein the process for generating a threshold signal includes, for the second switching period, determining a threshold signal value based on at least information associated with the one or more duty cycles; and generating the threshold signal equal to the determined threshold signal value, the threshold signal being constant in magnitude as a function of time for the second switching period.
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63-65. -65. (canceled)
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66-67. -67. (canceled)
Specification