Infineon Technologies Austria Ag

Tiam Poh Lau

Marcus Schaemann

Zhongfang Wang

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.

Over voltage protection in a voltage converter

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 () controls a primary side switch of the power converter based on both the supply voltage and the indication.

Power converter controller, power converter, and corresponding methods

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.

Overvoltage protection threshold based on previously sensed supply voltage

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.

Pulse modulation for isolated auxiliary voltage and dimming signal transfer over single opto-isolator

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.

System having a driver with voltage supply using an auxiliary winding of a transformer

A device includes light source and a controller. The light source includes a first LED coupled to a second LED, where a first terminal of the first LED is coupled to a first terminal of the second LED. The controller is configured to receive an input signal indicative of a color of light. The controller is also configured to adjust, based on the input signal, a first proportion of a current, the first proportion being applied to the first LED. The controller is also configured to adjust, based on the input signal, a second proportion of the current, the second proportion being applied to the second LED.

Tunable LED

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. Normal operation may resume if the power supply has no overvoltage events for a predetermined time period.

Adaptive open-load overvoltage control method and circuit

Representative implementations of devices and techniques provide a dimming arrangement for a variable load, such as a lamp. The dimming arrangement is coupled to a drive circuit for the load and arranged to reduce a drive current associated with the drive circuit, based on a control voltage.

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Tiam Poh Lau