LED lighting systems and methods for constant current control in various operation modes
First Claim
1. A system for providing at least an output current to one or more light emitting diodes, the system comprising:
- a transconductance amplifier configured to receive a sensed signal and also receive a predetermined voltage signal through a first switch, the sensed signal being associated with an inductor current flowing through an inductor coupled to a second switch, the transconductance amplifier being further configured to generate a current signal;
a capacitor coupled to the transconductance amplifier and configured to generate a voltage signal;
a comparator configured to process information associated with the voltage signal and a ramping signal and generate a comparison signal based on at least information associated with the voltage signal and the ramping signal;
a modulation-signal generator configured to receive at least the comparison signal and generate a modulation signal; and
a gate driver configured to receive the modulation signal and output a drive signal to the second switch;
wherein;
the drive signal is associated with at least one or more switching periods, each of the one or more switching periods including at least an on-time period for the second switch;
the transconductance amplifier is further configured to, for each of the one or more switching periods, receive at least a predetermined voltage signal only during the on-time period; and
the current signal is configured to charge or discharge the capacitor.
1 Assignment
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Accused Products
Abstract
System and method for providing at least an output current to one or more light emitting diodes. The system includes a control component configured to receive at least a demagnetization signal, a sensed signal and a reference signal and to generate a control signal based on at least information associated with the demagnetization signal, the sensed signal and the reference signal, and a logic and driving component configured to receive at least the control signal and output a drive signal to a switch based on at least information associated with the control signal. The switch is connected to a first diode terminal of a diode and a first inductor terminal of an inductor. The diode further includes a second diode terminal, and the inductor further includes a second inductor terminal.
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Citations
5 Claims
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1. A system for providing at least an output current to one or more light emitting diodes, the system comprising:
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a transconductance amplifier configured to receive a sensed signal and also receive a predetermined voltage signal through a first switch, the sensed signal being associated with an inductor current flowing through an inductor coupled to a second switch, the transconductance amplifier being further configured to generate a current signal; a capacitor coupled to the transconductance amplifier and configured to generate a voltage signal; a comparator configured to process information associated with the voltage signal and a ramping signal and generate a comparison signal based on at least information associated with the voltage signal and the ramping signal; a modulation-signal generator configured to receive at least the comparison signal and generate a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the second switch; wherein; the drive signal is associated with at least one or more switching periods, each of the one or more switching periods including at least an on-time period for the second switch; the transconductance amplifier is further configured to, for each of the one or more switching periods, receive at least a predetermined voltage signal only during the on-time period; and the current signal is configured to charge or discharge the capacitor. - View Dependent Claims (2, 3, 4)
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5. A method for providing at least an output current to one or more light emitting diodes, the method comprising:
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receiving at least a sensed signal, the sensed signal being associated with an inductor current flowing through an inductor coupled to a switch; processing information associated with the sensed signal and a predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; processing information associated with the current signal; generating a voltage signal, by at least a capacitor, based on at least information associated with the current signal; processing information associated with the voltage signal and a ramping signal; generating a comparison signal based on at least information associated with the voltage signal and the ramping signal; receiving at least the comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting a drive signal based on at least information associated with the modulation signal; wherein; the drive signal is associated with at least one or more switching periods, each of the one or more switching periods including at least an on-time period; and the process for receiving at least a sensed signal includes, for each of the one or more switching periods, receiving at least a predetermined voltage signal only during the on-time period; wherein the process for processing information associated with the current signal includes charging or discharging the capacitor with the current signal.
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Specification