Systems and methods for constant voltage mode and constant current mode in flyback power converters with primary-side sensing and regulation
First Claim
1. A system for regulating a power converter, the system comprising:
- a ramping signal generator configured to receive a demagnetization signal and generate a ramping signal;
a first comparator configured to receive the ramping signal and a first threshold signal and generate a first comparison signal based at least in part on the ramping signal and the first threshold signal;
a second comparator configured to receive a sensed signal and a second threshold signal and generate a second comparison signal, the sensed signal being associated with a current flowing through a primary winding of the power converter;
a drive signal generator configured to receive at least the first comparison signal and the second comparison signal and output a drive signal to a switch, the switch being configured to affect the current flowing through the primary winding;
wherein;
the demagnetization signal is associated with a demagnetization duration;
the drive signal is associated with a switching period; and
the system is further configured to keep a ratio of the demagnetization duration to the switching period constant.
1 Assignment
0 Petitions
Accused Products
Abstract
System and method for regulating a power converter. The system includes a first signal generator configured to receive a first sensed signal and generate an output signal associated with demagnetization. The first sensed signal is related to a first winding coupled to a secondary winding for a power converter, and the secondary winding is associated with at least an output current for the power converter. Additionally, the system includes a ramping signal generator configured to receive the output signal and generate a ramping signal, and a first comparator configured to receive the ramping signal and a first threshold signal and generate a first comparison signal based on at least information associated with the ramping signal and the first threshold signal. Moreover, the system includes a second comparator configured to receive a second sensed signal and a second threshold signal and generate a second comparison signal.
242 Citations
38 Claims
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1. A system for regulating a power converter, the system comprising:
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a ramping signal generator configured to receive a demagnetization signal and generate a ramping signal; a first comparator configured to receive the ramping signal and a first threshold signal and generate a first comparison signal based at least in part on the ramping signal and the first threshold signal; a second comparator configured to receive a sensed signal and a second threshold signal and generate a second comparison signal, the sensed signal being associated with a current flowing through a primary winding of the power converter; a drive signal generator configured to receive at least the first comparison signal and the second comparison signal and output a drive signal to a switch, the switch being configured to affect the current flowing through the primary winding; wherein; the demagnetization signal is associated with a demagnetization duration; the drive signal is associated with a switching period; and the system is further configured to keep a ratio of the demagnetization duration to the switching period constant. - View Dependent Claims (2, 3, 4)
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5. A system for regulating a power converter, the system comprising:
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an oscillator configured to receive a first control signal based at least in part on a demagnetization signal and generate a clock signal based at least in part on the first control signal; and a drive signal generator configured to receive the clock signal and a second control signal based at least in part on a first sensed signal, the first sensed signal being associated with a current flowing through a primary winding for a power converter, and output a drive signal to a switch, the switch being configured to affect the current flowing through the primary winding; wherein; the demagnetization signal is associated with a demagnetization duration; and the drive signal is associated with a switching period; wherein the system is further configured to; keep a ratio of the demagnetization duration to the switching period constant; and keep a peak of the first sensed signal constant in magnitude. - View Dependent Claims (6)
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7. A system for regulating a power converter, the system comprising:
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a first comparator configured to receive a first ramping signal based at least in part on a demagnetization signal and a first threshold signal and generate a first comparison signal based at least in part on the first ramping signal and the first threshold signal; a peak detector configured to receive a drive signal and a sensed signal and generate a peak signal, the sensed signal being associated with a current flowing through a primary winding of a power converter; an amplifier configured to receive the peak signal and a second threshold signal and generate an output signal with a capacitor; a second comparator configured to receive the output signal and a second ramping signal and generate a second comparison signal; and a drive signal generator configured to receive the first comparison signal and the second comparison signal and output the drive signal to the peak detector and a switch, the switch being configured to affect the current flowing through the primary winding. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A system for regulating a power converter, the system comprising:
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a peak detector configured to receive a drive signal and a sensed signal and generate a peak signal, the sensed signal being associated with a current flowing through a primary winding of a power converter; a signal generator configured to receive the peak signal and a demagnetization signal and generate a modulation signal; and a drive signal generator configured to receive the modulation signal and output the drive signal to the peak detector and a switch, the switch being configured to affect the current flowing through the primary winding; wherein; the demagnetization signal is associated with a demagnetization duration; and the drive signal is associated with a switching period; wherein the system is further configured to; keep a ratio of the demagnetization duration to the switching period constant;
orkeep an average magnitude of the peak signal over a first duration constant. - View Dependent Claims (14)
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15. A system for regulating a power converter, the system comprising:
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a first signal generator configured to receive a drive signal and a peak signal based at least in part on the drive signal and a sensed signal, the sensed signal being associated with a current flowing through a primary winding of a power converter, and generate a first output signal; an amplifier configured to receive the first output signal and a threshold signal and generate a second output signal with a capacitor; a comparator configured to receive the second output signal and a ramping signal and generate a comparison signal; a second signal generator configured to receive the comparison signal and a clock signal and generate a modulation signal; and a drive signal generator configured to receive the modulation signal and output the drive signal to a peak detector, the first signal generator and a switch, the switch being configured to affect the current flowing through the primary winding. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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24. A system for regulating a power converter, the system comprising:
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a first signal generator configured to receive a drive signal and a peak signal based at least in part on the drive signal and a sensed signal, the sensed signal being associated with a current flowing through a primary winding of a power converter, and generate a first output signal; an amplifier configured to receive the first output signal and a threshold signal and generate a second output signal with a capacitor; a second signal generator configured to receive the second output signal and a first input signal and generate a third output signal, the first input signal being proportional to a second input signal received by the primary winding; a comparator configured to receive the third output signal and the sensed signal and generate a comparison signal; a third signal generator configured to receive the comparison signal and a clock signal and generate a modulation signal; and a drive signal generator configured to receive the modulation signal and output the drive signal to a peak detector, the first signal generator, and a switch, the switch being configured to affect the current flowing through the primary winding. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31)
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32. A system for regulating a power converter, the system comprising:
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a first signal generator configured to receive a drive signal and a peak signal based at least in part on the drive signal and a first sensed signal, the first sensed signal being associated with a current flowing through a primary winding of a power converter, and generate a first output signal; an amplifier configured to receive the first output signal and a threshold signal and generate a second output signal with a capacitor; a second signal generator configured to receive a second sensed signal, the second output signal and the drive signal and generate a third output signal; a comparator configured to receive the third output signal and the first sensed signal and generate a comparison signal; a third signal generator configured to receive the comparison signal and a clock signal and generate a modulation signal; and a drive signal generator configured to receive the modulation signal and output the drive signal to a peak detector, the first signal generator, the second signal generator, and a first switch, the first switch being configured to affect the current flowing through the primary winding. - View Dependent Claims (33, 34, 35, 36, 37)
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38. A system for regulating a power converter, the system comprising:
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a signal generator configured to receive a peak signal and a demagnetization signal and generate a modulation signal; and a drive signal generator configured to receive the modulation signal based at least in part on the peak signal and a demagnetization and output a drive signal to a peak detector and a switch, the switch being configured to affect a current flowing through a primary winding of a power converter; wherein; the peak signal is based at least in part on the drive signal and a sensed signal; the sensed signal is associated with the current flowing through the primary winding of the power converter; the drive signal is associated with a switching period; the demagnetization signal is associated with a demagnetization duration; and the demagnetization duration multiplied by the peak signal in magnitude is equal to a demagnetization peak value; wherein the system is further configured to; keep the switching period constant; keep an average magnitude of the demagnetization peak value over a first duration constant; and keep an output current associated with a secondary winding of the power converter constant.
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Specification