Abstract: An apparatus (such as a power converter circuit) includes s primary winding, an auxiliary winding, and an over-voltage protection circuit (such as a controller and corresponding one or more circuit components). The primary winding receives an input voltage. The auxiliary winding is magnetically coupled to the primary winding. The primary winding receives energy from the input voltage, the auxiliary winding receives the energy from the primary winding. The over-voltage protection circuit controls conveyance of the energy received from the primary winding through a discharge circuit path to a reference voltage (such as ground). Conveyance of the energy (as received from the auxiliary winding) associated with the input voltage through the discharge circuit path prevents damage to a respective power converter circuit during exposure of the input voltage to a power surge condition such as due to lightning.

Abstract: An apparatus (such as a power converter circuit) includes s primary winding, an auxiliary winding, and an over-voltage protection circuit (such as a controller and corresponding one or more circuit components). The primary winding receives an input voltage. The auxiliary winding is magnetically coupled to the primary winding. The primary winding receives energy from the input voltage, the auxiliary winding receives the energy from the primary winding. The over-voltage protection circuit controls conveyance of the energy received from the primary winding through a discharge circuit path to a reference voltage (such as ground). Conveyance of the energy (as received from the auxiliary winding) associated with the input voltage through the discharge circuit path prevents damage to a respective power converter circuit during exposure of the input voltage to a power surge condition such as due to lightning.

Abstract: Power converter controllers, power converters and corresponding methods are provided. A power converter controller may have a first input for receiving an indication of an output of the power converter and a second input operative to receive a supply voltage. A control circuit of the power converter controller (10) controls a primary side switch of the power converter based on both the supply voltage and the indication.

Abstract: A device for overvoltage protection includes a gate driver module and an overvoltage protection module. The gate driver module is configured to selectively activate a switching element to provide input power to a primary side winding of a transformer for generating a target output at a secondary side winding of the transformer. The overvoltage protection module is configured to determine a transition threshold based on a previously sensed supply voltage at a voltage supply pin configured to receive power for operating the circuit from a primary side auxiliary winding of the transformer and determine the circuit is operating in an overvoltage condition when a current supply voltage at the voltage supply pin exceeds the transition threshold, wherein the current supply voltage occurs at the supply pin after the previously sensed supply voltage.

Abstract: Power converter controllers, power converters and corresponding methods are provided. A power converter controller may have a first input for receiving an indication of an output of the power converter and a second input operative to receive a supply voltage. A control circuit of the power converter controller (10) controls a primary side switch of the power converter based on both the supply voltage and the indication.

Abstract: An example relates to a method for operating a converter comprising a primary side of a transformer and a secondary side of the transformer, wherein a switching element is used for conveying energy from the primary side to the secondary side, the method comprising (i) determining a voltage drop across the primary side of the transformer; (ii) determining at least one additional voltage drop across at least one component of the converter's primary side; and (iii) determining an input voltage at the converter via the voltage drops.

Abstract: Techniques are described to adjust the time when a switch is turned on from the time of one voltage valley to the time of another voltage valley for controlling an average load current or average load voltage. In some examples, the adjustment is instantaneous, and in some examples, the adjustment is gradual. Both of these example techniques provide for high switching efficiency of the switch.

Abstract: In an example, a controller that controls one or more light-emitting diodes (LEDs), wherein the controller is configured to receive an output voltage from a secondary transformer winding of a transformer, and receive first information across a galvanic isolation barrier, wherein the first information includes a desired LED brightness. The controller is further configured to receive second information across the galvanic isolation barrier, and the second information includes an output voltage of an auxiliary transformer winding; The controller may control the one or more LEDs based on the first information, and also control the output voltage of a secondary transformer winding and the output voltage of the auxiliary transformer winding based on the first information and the second information.

Abstract: A drive circuit and a method are disclosed. The drive circuit includes output nodes configured to be coupled to a load, a capacitor coupled between the output nodes, and a power converter. The power converter is configured to store an initialization value in a memory in at least one of a plurality of on-phases of the drive circuit and to control an initialization phase of at least one other of the plurality of on-phases based on the initialization value stored in the memory. The initialization value is dependent on an output voltage across the capacitor during a load drive phase of the at least one on-phase, and the power converter is further configured to regulate an output current during the load drive phase.

Abstract: In one example, a system includes a controller, a transformer including at least a primary winding and an auxiliary winding, a voltage supply, and a driver. The controller is configured to output an indication of a target current or a target power. The voltage supply is configured to receive an electrical current having a constant average current over time from the auxiliary winding and to output variable electrical current for supplying the controller. The voltage supply includes a capacitor for storing energy and a current sink for consuming a current. The driver is configured to selectively energize the primary winding for supplying one or more load devices based on the target current or the target power and selectively energize the primary winding for operating the voltage supply based on an indication of a voltage at the voltage supply.

Abstract: In accordance with an embodiment, a method of operating a power system includes operating a power converter at a first output power, monitoring a first input voltage at an input port of the power converter. The method further includes upon detecting that the first input voltage drops below a first pre-determined voltage threshold, reducing the first output power of the power converter to a second output power lower than the first output power, and suspending operation of the power converter after the reducing the first output power of the power converter.

Abstract: An overvoltage protection circuit and a method for protecting against an output from a power supply reaching overvoltage levels is provided. The overvoltage protection provides two operational modes for the power supply. In both modes, the overvoltage protection monitors the output voltage of the power supply and disables it if the output voltage reaches a threshold indicating an overvoltage event. In normal operation, this threshold is set to a level that is higher than a nominal safety threshold defined for the power supply whereas in reduced operation, this threshold is set to a value lower than the safety threshold. When an overvoltage event is detected in normal operation, the overvoltage protection transitions the power supply into the reduced operational mode before reactivating it. The power supply may be reactivated, produce an overvoltage event, and be deactivated multiple times in the reduced operational mode.

Abstract: An example relates to a method for operating a converter comprising (i) determining whether a valley for switching the converter in a quasi-resonant mode is available within a predetermined time range; (ii) selecting the valley if it is available within the predetermined time range; and (iii) changing the mode for operating the converter if the valley is not available within the predetermined time range.

Abstract: According to an embodiment, a switched-mode power supply (SMPS) includes a controller including a measurement circuit and a pulse width modulator having an output configured to be coupled to a control node of a switch of the SMPS. The measurement circuit is configured to determine a phase angle of an AC line input of the SMPS and modulate a frequency of a control signal at the output of the pulse width modulator based on the phase angle.

Abstract: In accordance with an embodiment, a method of operating a power system includes operating a power converter at a first output power, monitoring a first input voltage at an input port of the power converter. The method further includes upon detecting that the first input voltage drops below a first pre-determined voltage threshold, reducing the first output power of the power converter to a second output power lower than the first output power, and suspending operation of the power converter after the reducing the first output power of the power converter.

Abstract: An overvoltage protection circuit and a method for protecting against an output from a power supply reaching overvoltage levels is provided. The overvoltage protection provides two operational modes for the power supply. In both modes, the overvoltage protection monitors the output voltage of the power supply and disables it if the output voltage reaches a threshold indicating an overvoltage event. In normal operation, this threshold is set to a level that is higher than a nominal safety threshold defined for the power supply whereas in reduced operation, this threshold is set to a value lower than the safety threshold. When an overvoltage event is detected in normal operation, the overvoltage protection transitions the power supply into the reduced operational mode before reactivating it. The power supply may be reactivated, produce an overvoltage event, and be deactivated multiple times in the reduced operational mode.

Abstract: The time when a switch is turned on from the time of one voltage valley to the time of another voltage valley may be adjusted for controlling an average load current or average load voltage. In some examples, the adjustment is instantaneous, and in some examples, the adjustment is gradual. Both of these example techniques provide for high switching efficiency of the switch.

Abstract: An example relates to a method for operating a converter comprising a primary side of a transformer and a secondary side of the transformer, wherein a switching element is used for conveying energy from the primary side to the secondary side, the method comprising (i) determining a voltage drop across the primary side of the transformer; (ii) determining at least one additional voltage drop across at least one component of the converter's primary side; and (iii) determining an input voltage at the converter via the voltage drops.

Abstract: An example relates to a method for operating a converter comprising (i) determining whether a valley for switching the converter in a quasi-resonant mode is available within a predetermined time range; (ii) selecting the valley if it is available within the predetermined time range; and (iii) changing the mode for operating the converter if the valley is not available within the predetermined time range.

Abstract: A power converter is described that includes a switch. The power converter may also include a controller that controls the switch. The controller may be configured to ascertain a first parameter. Additionally, the controller may be configured to ascertain a second parameter. The controller may dynamically modulate duty cycle of the switch based on the first parameter and the second parameter in addition and independent of the control loop.