Abstract: An apparatus includes a primary controller coupled to a primary circuit, a secondary controller coupled to a secondary circuit and configured to detect a load condition, wherein the secondary controller is configured to in response to detecting a load disconnection, pull down a secondary feedback node for a first predetermined time to signal the primary controller to reduce bias power, and then configure the secondary feedback node as a high impedance node, and in response to detecting a load reconnection, pull down the secondary feedback node for a second predetermined time to wake the primary controller, and wherein the primary controller is configured to detect whether a voltage on the primary feedback node falls below a threshold for at least a third predetermined time, and in response thereto, disable a feedback control loop of the isolated power converter to enter a sleep state.

Abstract: An apparatus includes a secondary controller coupled to a secondary circuit of a power conversion system, and a primary controller coupled to a primary circuit of the power conversion system, the primary controller being coupled to the secondary controller through an isolation interface, wherein the secondary controller is configured to detect whether a load is coupled to the power conversion system, in response to the load being disconnected from the power conversion system, communicate with the primary controller through pulling down a secondary feedback node in the secondary circuit and a primary feedback node in the primary circuit for a first predetermined time, provide a high impedance at the secondary feedback node to reduce power consumption, and in response to the load being reconnected to the power conversion system, communicate with the primary controller through pulling down the secondary feedback node in the secondary circuit for a second predetermined time.

Abstract: A control circuit is coupled to a power converter having an input voltage VIN and an output voltage VOUT. The control circuit includes a capacitor connected between a current source and a ground. The current source is configured to charge the capacitor with a current ?VIN or ?(VIN?VOUT) when a pulse width modulate (PWM) signal of a PWM controller of the power converter is high, and to discharge the capacitor with a current ?(?VOUT) or ?(VIN?VOUT) when the PWM signal is low. ? is a pre-configured constant. The control circuit is configured to trigger the PWM controller to skip pulses when a voltage across the capacitor decreases to be less than a threshold before a present switching cycle of the power converter ends.

Abstract: An apparatus includes a secondary controller coupled to a secondary circuit of a power conversion system, and a primary controller coupled to a primary circuit of the power conversion system, the primary controller being coupled to the secondary controller through an isolation interface, wherein the secondary controller is configured to detect whether a load is coupled to the power conversion system, in response to the load being disconnected from the power conversion system, communicate with the primary controller through pulling down a secondary feedback node in the secondary circuit and a primary feedback node in the primary circuit for a first predetermined time, provide a high impedance at the secondary feedback node to reduce power consumption, and in response to the load being reconnected to the power conversion system, communicate with the primary controller through pulling down the secondary feedback node in the secondary circuit for a second predetermined time.

Abstract: In a power supply having a control circuit for regulating the power supply output and a load switch for connecting the output to a load device, a method for reducing standby power includes determining if a load device is connected to the power supply. If no load device is connected, the load switch is turned off, and the power supply enters a standby mode, which includes alternating first time period of power-saving mode and second time period of regulating mode. In the power-saving mode, the control circuit stops regulating the output of the power supply and turns off one or more functional blocks to allow the output to drop, until the output reaches a pre-set low output limit. In the regulating mode, the control circuit turns on the functional blocks and regulates the power supply to allow the output to increase, until the output reaches a pre-set high output limit.

Abstract: In a power supply having a control circuit for regulating the power supply output and a load switch for connecting the output to a load device, a method for reducing standby power includes determining if a load device is connected to the power supply. If no load device is connected, the load switch is turned off, and the power supply enters a standby mode, which includes alternating first time period of power-saving mode and second time period of regulating mode. In the power-saving mode, the control circuit stops regulating the output of the power supply and turns off one or more functional blocks to allow the output to drop, until the output reaches a pre-set low output limit. In the regulating mode, the control circuit turns on the functional blocks and regulates the power supply to allow the output to increase, until the output reaches a pre-set high output limit.

Abstract: A power supply includes a power converter configured to convert an input voltage to a target output DC voltage in response to a feedback signal, the feedback signal having a value. The power supply also includes a regulator coupled to the power converter and configured to generate an output power status signal, which maybe in one of two states depending whether an output current from the regulator is above or below a target current over a preset time duration. Further, a control circuit is coupled to the power converter and to the regulator and configured to increment or decrement the value of the feedback signal depending on the state of the power status signal.

Abstract: A control circuit includes an input terminal for receiving an input signal, which maybe either a digital input signal or an analog input signal, and the control circuit is configured to provide a digital control signal in response to the input signal. The control circuit may include a mode detection circuit for determining whether the input signal is a digital signal or an analog signal and providing a mode signal, a multiplexer circuit configured to select either a digital reference signal or an analog reference signal in response to the mode signal, and a comparator configured for comparing the input signal with the reference signal selected by the multiplexer to provide the PWM control signal.

Abstract: A power supply includes a power converter configured to convert an input voltage to a target output DC voltage in response to a feedback signal, the feedback signal having a value. The power supply also includes a regulator coupled to the power converter and configured to generate an output power status signal, which may be in one of two states depending whether an output current from the regulator is above or below a target current over a preset time duration. Further, a control circuit is coupled to the power converter and to the regulator and configured to increment or decrement the value of the feedback signal depending on the state of the power status signal.

Abstract: A power supply includes a power converter configured to convert an input voltage to a target output DC voltage in response to a feedback signal, the feedback signal having a value. The power supply also includes a regulator coupled to the power converter and configured to generate an output power status signal, which maybe in one of two states depending whether an output current from the regulator is above or below a target current over a preset time duration. Further, a control circuit is coupled to the power converter and to the regulator and configured to increment or decrement the value of the feedback signal depending on the state of the power status signal.

Abstract: A multiple channel current regulator is configured to deliver a maximum current to a load associated with the channel in a lighting system. Different channels may have a different maximum current and the ratio among the maximum currents is fixed. In operation, the current of each channel can be individually modulated by a pulse stream that controls the current that flows to the load.

Abstract: A power supply includes a power converter configured to convert an input voltage to a target output DC voltage in response to a feedback signal, the feedback signal having a value. The power supply also includes a regulator coupled to the power converter and configured to generate an output power status signal, which maybe in one of two states depending whether an output current from the regulator is above or below a target current over a preset time duration. Further, a control circuit is coupled to the power converter and to the regulator and configured to increment or decrement the value of the feedback signal depending on the state of the power status signal.

Abstract: A control circuit includes an input terminal for receiving an input signal, which maybe either a digital input signal or an analog input signal, and the control circuit is configured to provide a digital control signal in response to the input signal. The control circuit may include a mode detection circuit for determining whether the input signal is a digital signal or an analog signal and providing a mode signal, a multiplexer circuit configured to select either a digital reference signal or an analog reference signal in response to the mode signal, and a comparator configured for comparing the input signal with the reference signal selected by the multiplexer to provide the PWM control signal.