Abstract: System and method for discharging a capacitor. An example system includes a signal detector and a discharge control component. The signal detector is configured to receive an input signal and generate a detection signal based on at least information associated with the input signal, the input signal being associated with an alternate current signal received by a capacitor including a first capacitor terminal and a second capacitor terminal. The discharge control component configured to receive at least the detection signal and generate an output signal to discharge the capacitor if the detection signal satisfies one or more conditions.

Abstract: Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different.

Abstract: System and method for protecting a power converter. The system includes a first comparator configured to receive a first threshold signal and a first signal and to generate a first comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a second comparator configured to receive a second threshold signal and the first signal and to generate a second comparison signal. The second threshold signal is different from the first threshold signal in magnitude. Moreover, the system includes a first detection component configured to receive at least the second comparison signal, detect the second comparison signal only if one or more predetermined conditions are satisfied, and generate a first detection signal based on at least information associated with the detected second comparison signal.

Abstract: System and method for regulating a power conversion system. For example, a system controller for regulating a power conversion system includes an amplifier, a variable-resistance component, a capacitor, and a modulation and drive component. The amplifier is configured to receive a reference signal and a feedback signal associated with an output signal of the power conversion system, the amplifier including an amplifier terminal. The variable-resistance component is associated with a first variable resistance value, the variable-resistance component including a first component terminal and a second component terminal, the first component terminal being coupled with the amplifier terminal. The capacitor includes a first capacitor terminal and a second capacitor terminal, the first capacitor terminal being coupled with the second component terminal. The modulation and drive component includes a first terminal and a second terminal, the first terminal being coupled with the amplifier terminal.

Abstract: System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal and a second controller terminal. The system controller is configured to receive at least an input signal at the first controller terminal, and generate a gate drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to, if the input signal is larger than a first threshold, generate the gate drive signal at a first logic level to turn off the transistor.

Abstract: System and method for protecting a power conversion system. An example system controller includes a protection component and a driving component. The protection component is configured to receive a demagnetization signal generated based on at least information associated with a feedback signal of the power conversion system, process information associated with the demagnetization signal and a detected voltage generated based on at least information associated with the feedback signal, and generate a protection signal based on at least information associated with the detected voltage and the demagnetization signal. The driving component is configured to receive the protection signal and output a driving signal to a switch configured to affect a primary current flowing through a primary winding of the power conversion system. The detected voltage is related to an output voltage of the power conversion system. The demagnetization signal is related to a demagnetization period of the power conversion system.

Abstract: System and method for regulating a power converter. The system includes a first signal processing component configured to receive at least a sensed signal and generate a first signal. The sensed signal is associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter. Additionally, the system includes a second signal processing component configured to generate a second signal, an integrator component configured to receive the first signal and the second signal and generate a third signal, and a comparator configured to process information associated with the third signal and the sensed signal and generate a comparison signal based on at least information associated with the third signal and the sensed signal.

Abstract: System and method are provided for regulating a power converter. The system includes a signal processing component configured to receive a first input signal and a second input signal, process information associated with the first input signal and the second input signal, and output a drive signal to a switch based on at least information associated with the first input signal and the second input signal. The first input signal is associated with at least a feedback signal related to an output voltage of the power converter. The second input signal is associated with at least a primary current flowing through a primary winding of the power converter. The signal processing component is further configured to change a peak value of the primary current within a first predetermined range, and change the switching frequency of the power converter within a second predetermined range.

Abstract: System and method for protecting a power conversion system. An example system controller includes a protection component and a driving component. The protection component is configured to receive a feedback signal, a reference signal, and a demagnetization signal generated based on at least information associated with the feedback signal, process information associated with the feedback signal, the reference signal, and the demagnetization signal, and generate a protection signal based on at least information associated with the feedback signal, the reference signal, and the demagnetization signal. The demagnetization signal is related to multiple demagnetization periods of the power conversion system, the multiple demagnetization periods including a first demagnetization period and a second demagnetization period.

Abstract: System and method are provided for regulating a string current flowing through a string of one or more light emitting diodes. A system controller includes a first controller terminal, a second controller terminal and a third controller terminal. The first controller terminal is coupled to a base terminal of a bipolar junction transistor, the bipolar junction transistor further including an emitter terminal and a collector terminal, the collector terminal being connected to the string of one or more light emitting diodes. The second controller terminal is coupled to the emitter terminal of the bipolar junction transistor and to a first resistor terminal of a resistor associated with a resistance. The third controller terminal is coupled to a second resistor terminal of the resistor. In addition, the system controller is configured to receive a reference voltage, receive an emitter voltage, and output a base current.

Abstract: System and method for dimming control. The system includes a system controller, a transistor, and a resistor. The system controller includes a first controller terminal and a second controller terminal. The transistor includes a first transistor terminal, a second transistor terminal and a third transistor terminal. The resistor including a first resistor terminal and a second resistor terminal. The first transistor terminal is coupled, directly or indirectly, to the second controller terminal. The first resistor terminal is coupled to the second transistor terminal. The second resistor terminal is coupled to the third transistor terminal. The system controller is configured to receive an input signal at the first controller terminal and to generate an output signal at the second controller terminal. The transistor is configured to receive the output signal at the first transistor terminal and to change between a first condition and a second condition.

Abstract: System and method are provided for driving a transistor. The system includes a floating-voltage generator, a first driving circuit, and a second driving circuit. The floating-voltage generator is configured to receive a first bias voltage and generate a floating voltage, the floating-voltage generator being further configured to change the floating voltage if the first bias voltage changes and to maintain the floating voltage to be lower than the first bias voltage by a first predetermined value in magnitude. The first driving circuit is configured to receive an input signal, the first bias voltage and the floating voltage. The second driving circuit is configured to receive the input signal, a second bias voltage and a third bias voltage, the first driving circuit and the second driving circuit being configured to generate an output signal to drive a transistor.

Abstract: Systems and methods are provided for regulating a power conversion system. An example system controller includes a driving component and a detection component. The driving component is configured to output a driving signal to a switch associated with a first current flowing through a primary winding of a power conversion system, the switch including a first switch terminal related to a first voltage and a second switch terminal related to a second voltage, the driving signal being associated with a plurality of switching periods. The detection component is configured to receive an input signal associated with a difference between the first voltage and the second voltage, detect at least one valley of the input signal in magnitude during a detection period for the first switching period, and output a detection signal based on at least information associated with the input signal to affect the driving signal.

Abstract: Oscillator system and method thereof. The oscillator system includes a first voltage-to-current converter configured to receive a first voltage and generate a first current based on at least information associated with the first voltage, and a second voltage-to-current converter configured to receive a second voltage and generate a second current based on at least information associated with the second voltage. Additionally, the oscillator system further includes a current-mode N-bit digital-to-analog converter configured to receive at least the second current and a first clock signal and to generate a third current based on at least information associated with the second current and the first clock signal. N is a first integer. The first clock signal is associated with a first clock frequency corresponding to a first clock period. Moreover, the oscillator system further includes a current comparator coupled to the first voltage-to-current converter and the current-mode N-bit digital-to-analog converter.

Abstract: System and method for regulating a power conversion system. An example system controller for regulating a power conversion system includes a signal generator and a driving component. The signal generator is configured to receive a feedback signal associated with an output signal of a power conversion system and a current sensing signal associated with a primary current flowing through a primary winding of the power conversion system and generate a modulation signal based on at least information associated with the feedback signal and the current sensing signal. The driving component is configured to receive the modulation signal and output a drive signal to a switch based on at least information associated with the modulation signal.

Abstract: System and method for dimming control. The system includes a system controller, a transistor, and a resistor. The system controller includes a first controller terminal and a second controller terminal. The transistor includes a first transistor terminal, a second transistor terminal and a third transistor terminal. The resistor including a first resistor terminal and a second resistor terminal. The first transistor terminal is coupled, directly or indirectly, to the second controller terminal. The first resistor terminal is coupled to the second transistor terminal. The second resistor terminal is coupled to the third transistor terminal. The system controller is configured to receive an input signal at the first controller terminal and to generate an output signal at the second controller terminal. The transistor is configured to receive the output signal at the first transistor terminal and to change between a first condition and a second condition.

Abstract: System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal, a second controller terminal and a third controller terminal. The system controller is configured to receive an input signal at the first controller terminal and turn on or off a switch based on at least information associated with the input signal to adjust a primary current flowing through a primary winding of the power conversion system, receive a first signal at the second controller terminal from the switch, and charge a capacitor through the third controller terminal in response to the first signal.

Abstract: System and method for regulating a power conversion system. For example, a system controller for regulating a power conversion system includes an amplifier, a variable-resistance component, a capacitor, and a modulation and drive component. The amplifier is configured to receive a reference signal and a feedback signal associated with an output signal of the power conversion system, the amplifier including an amplifier terminal. The variable-resistance component is associated with a first variable resistance value, the variable-resistance component including a first component terminal and a second component terminal, the first component terminal being coupled with the amplifier terminal. The capacitor includes a first capacitor terminal and a second capacitor terminal, the first capacitor terminal being coupled with the second component terminal. The modulation and drive component includes a first terminal and a second terminal, the first terminal being coupled with the amplifier terminal.

Abstract: Systems and methods for dimming control using TRIAC dimmers are provided. An example apparatus for a power conversion system includes: a process-and-drive component configured to receive an input signal and output a drive signal to a switch to affect a current that flows through a primary winding of a power conversion system. The input signal includes a first pulse associated with a first input period and a second pulse associated with a second input period. The drive signal is associated with a first modulation period for the first input period and a second modulation period for the second input period. The process-and-drive component is further configured to: determine the first modulation period for the first input period; change the drive signal between a first logic level and a second logic level at a modulation frequency during the first modulation period; determine the second modulation period for the second input period.

Abstract: Systems and methods for dimming control using TRIAC dimmers are provided. An example apparatus for a power conversion system includes: a process-and-drive component configured to receive an input signal and output a drive signal to a switch to affect a current that flows through a primary winding of a power conversion system. The input signal includes a first pulse associated with a first input period and a second pulse associated with a second input period. The drive signal is associated with a first modulation period for the first input period and a second modulation period for the second input period. The process-and-drive component is further configured to: determine the first modulation period for the first input period; change the drive signal between a first logic level and a second logic level at a modulation frequency during the first modulation period; determine the second modulation period for the second input period.