Abstract: System and method for controlling synchronous rectification. For example, the system for controlling synchronous rectification includes: a switch including a first switch terminal configured to receive a first voltage, the switch further including a second switch terminal and being configured to be closed or opened by a control signal; a voltage generator configured to receive a second voltage from the second switch terminal and generate a third voltage based at least in part on the second voltage; a filter circuit including a resistor and a capacitor, the filter circuit being configured to receive the second voltage from the second switch terminal and generate a fourth voltage based at least in part on the second voltage; a first comparator configured to receive the third voltage and the fourth voltage and generate a first comparison signal based at least in part on the third voltage and the four voltage.

Abstract: System and method for synchronous rectification of a power converter. For example, the system for synchronous rectification includes: a first system terminal configured to receive an input voltage; and a second system terminal configured to output a drive signal to a first transistor terminal of a transistor, the transistor further including a second transistor terminal and a third transistor terminal, the second transistor terminal being connected to a secondary winding of the power converter, the power converter further including a primary winding coupled to the secondary winding; wherein the system is configured to: determine whether the input voltage becomes lower than a predetermined voltage threshold; and if the input voltage becomes lower than the predetermined voltage threshold, determine whether a time when the input voltage becomes lower than the predetermined voltage threshold is during or not during a demagnetization process of the secondary winding.

Abstract: System and method for controlling synchronous rectification. For example, the system for controlling synchronous rectification includes: a switch including a first switch terminal configured to receive a first voltage, the switch further including a second switch terminal and being configured to be closed or opened by a control signal; a voltage generator configured to receive a second voltage from the second switch terminal and generate a third voltage based at least in part on the second voltage; a filter circuit including a resistor and a capacitor, the filter circuit being configured to receive the second voltage from the second switch terminal and generate a fourth voltage based at least in part on the second voltage; a first comparator configured to receive the third voltage and the fourth voltage and generate a first comparison signal based at least in part on the third voltage and the four voltage.

Abstract: Controller and method for a power converter. For example, a controller for a power converter includes: a mode detector configured to determine a mode of operation for the power converter; a first gate driver configured to output a first drive voltage to a first transistor related to a first auxiliary winding coupled to a primary winding, a secondary winding, and a second auxiliary winding; a second gate driver configured to output a second drive voltage to a second transistor related to the primary winding; wherein the first gate driver is further configured to, if the mode of operation satisfies one or more first predetermined conditions, generate the first drive voltage so that the first transistor remains turned off during a switching cycle of the power converter.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to receive an input signal at the first controller terminal and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power converter. Additionally, the system controller is further configured to determine whether the input signal remains larger than a first threshold for a first time period that is equal to or longer than a first predetermined duration.

Abstract: System and method for controlling synchronous rectification. For example, the system for controlling synchronous rectification includes: a switch including a first switch terminal configured to receive a first voltage, the switch further including a second switch terminal and being configured to be closed or opened by a control signal; a voltage generator configured to receive a second voltage from the second switch terminal and generate a third voltage based at least in part on the second voltage; a filter circuit including a resistor and a capacitor, the filter circuit being configured to receive the second voltage from the second switch terminal and generate a fourth voltage based at least in part on the second voltage; a first comparator configured to receive the third voltage and the fourth voltage and generate a first comparison signal based at least in part on the third voltage and the four voltage.

Abstract: Controller and method for a power converter. For example, a controller for a power converter includes: a first gate driver configured to output a first drive signal to a first transistor related to a primary winding, the first transistor including a drain terminal and a source terminal, the primary winding being configured to receive an input voltage, the primary being coupled to a first auxiliary winding and a second auxiliary winding; one or more voltage detectors configured to generate a first detection signal and a second detection signal based at least in part on a current signal related to the first auxiliary winding; a time controller configured to receive the first detection signal and the second detection signal and generate a control signal based at least in part on the first detection signal and the second detection signal; and a second gate driver configured to receive the control signal.

Abstract: System and method for synchronous rectification of a power converter. For example, the system for synchronous rectification includes: a first system terminal configured to receive an input voltage; and a second system terminal configured to output a drive signal to a first transistor terminal of a transistor, the transistor further including a second transistor terminal and a third transistor terminal, the second transistor terminal being connected to a secondary winding of the power converter, the power converter further including a primary winding coupled to the secondary winding; wherein the system is configured to: determine whether the input voltage becomes lower than a predetermined voltage threshold; and if the input voltage becomes lower than the predetermined voltage threshold, determine whether a time when the input voltage becomes lower than the predetermined voltage threshold is during or not during a demagnetization process of the secondary winding.

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. Additionally, the system controller is configured to receive an input signal at the first controller terminal, and generate a drive signal at the second controller terminal based at least in part on 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. Moreover, the system controller is further configured to determine whether the input signal is larger than a first threshold at a first time, in response to the input signal being determined to be larger than the first threshold at the first time, determine whether the input signal is smaller than a second threshold at a second time.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to receive an input signal at the first controller terminal and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power converter. Additionally, the system controller is further configured to determine whether the input signal remains larger than a first threshold for a first time period that is equal to or longer than a first predetermined duration.

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 controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to: receive, at the first controller terminal, an input signal; generate a drive signal based at least in part on the input signal, the drive signal being associated with an on-time period and an off-time period, the on-time period including a first beginning and a first end; and output, at the second controller terminal, the drive signal to a switch to close the switch during the on-time period and open the switch during the off-time period to affect a current associated with a secondary winding of the power converter. The system controller is further configured to detect a demagnetization period associated with the secondary winding based at least in part on the input signal.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to receive an input signal at the first controller terminal and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power converter. Additionally, the system controller is further configured to determine whether the input signal remains larger than a first threshold for a first time period that is equal to or longer than a first predetermined duration.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to receive an input signal at the first controller terminal and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power converter. Additionally, the system controller is further configured to determine whether the input signal remains larger than a first threshold for a first time period that is equal to or longer than a first predetermined duration.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to receive, at the first controller terminal, an input signal, generate a drive signal based at least in part on the input signal, and output, at the second controller terminal, the drive signal to a switch to affect a current associated with a secondary winding of the power converter. The system controller is further configured to detect a first duration of a demagnetization period associated with the secondary winding based at least in part on the input signal, determine a second duration of a time period for the drive signal based at least in part on the first duration, and keep the drive signal at a first logic level during the entire time period.

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. Additionally, the system controller is configured to receive an input signal at the first controller terminal, and generate a drive signal at the second controller terminal based at least in part on 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. Moreover, the system controller is further configured to determine whether the input signal is larger than a first threshold at a first time, in response to the input signal being determined to be larger than the first threshold at the first time, determine whether the input signal is smaller than a second threshold at a second time.

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. Additionally, the system controller is configured to receive an input signal at the first controller terminal, and generate a drive signal at the second controller terminal based at least in part on 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. Moreover, the system controller is further configured to determine whether the input signal is larger than a first threshold at a first time, in response to the input signal being determined to be larger than the first threshold at the first time, determine whether the input signal is smaller than a second threshold at a second time.

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.

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.