Abstract: A circuit arrangement comprises an LED chain comprising multiple LEDs and bypass switching elements, wherein each LED is assigned to one of the bypass switching elements, and the bypass switching elements each have a driver terminal, wherein each of the bypass switching elements is configured to bypass the LED of the LED chain that is associated with the bypass switching element based on a voltage at the driver terminal that is associated with the bypass switching element; and a switch, wherein the driver terminals of the bypass switching elements are connected to the switch via a common node, the switch being configured to discharge a capacitor of a constant current source that can be connected to the LED chain based on a voltage applied to the node. A circuit comprises the circuit arrangement.

Abstract: A method carries out a self-test of an electrical converter circuit, by use of a control device, proceeding from a known operating point at which a predetermined electrical operating variable has a predetermined starting value, a measurement cycle is begun by the converter circuit being operated. It is additionally provided that the time since the starting of the measurement cycle is detected, and the electrical operating variable and the time constitute two monitoring variables of the self-test. The measurement cycle is ended if one of the two monitoring variables satisfies an ending criterion. A test value is then formed from a measurement value of the other of the two monitoring variables at the end of the measurement cycle and a check is made to ascertain whether the test value lies outside a predetermined reference interval. If so an error signal is generated.

Abstract: A method carries out a self-test of an electrical converter circuit, by use of a control device, proceeding from a known operating point at which a predetermined electrical operating variable has a predetermined starting value, a measurement cycle is begun by the converter circuit being operated. It is additionally provided that the time since the starting of the measurement cycle is detected, and the electrical operating variable and the time constitute two monitoring variables of the self-test. The measurement cycle is ended if one of the two monitoring variables satisfies an ending criterion. A test value is then formed from a measurement value of the other of the two monitoring variables at the end of the measurement cycle and a check is made to ascertain whether the test value lies outside a predetermined reference interval. If so an error signal is generated.

Abstract: A method for monitoring an AC voltage source, which is DC-decoupled from a reference potential and which generates an AC voltage between two AC voltage lines. Each of the AC voltage lines is coupled to the reference potential by way of a respective capacitive voltage divider and a respective component voltage signal is tapped at the voltage dividers and at least one root mean square value signal is generated therefrom and a check is carried out to determine whether the respective root mean square value signal meets a predetermined triggering criterion. When the triggering criterion is met, a fault signal is generated.

Abstract: The disclosure relates to an electronic module comprising a source terminal for receiving an input current from an electrical voltage source and comprising an electrical input capacitance which is effective with respect to the source terminal, wherein the input capacitance is connected to the source terminal via a transistor circuit. The disclosure additionally provides that the transistor circuit is configured to conduct the input current via a respective switching path of at least one transistor, and a control device is configured to switch, during the switch-on process for limiting the input current, a control voltage at a respective control terminal of the at least one transistor, in a plurality of steps, from an off value at which each switching path is switched off, to a connection value at which a contact resistance of each switching path is minimized.

Abstract: A method operates a DC-DC voltage converter. A current measurement circuit generates a current signal correlated with a coil current of a coil. A hysteretic switch control system electrically turns off a switch for driving the coil current, if the current signal signals a coil current greater than a peak comparison value, and electrically turns on the switch if the current signal signals a coil current lower than a valley comparison value. An actual value measurement circuit generates an actual value signal correlated with an electrical output variable of the DC-DC voltage converter. A controller unit adjusts the output variable to a prescribed setpoint value and, generates a comparison value signal depending on a control deviation and the switch control system sets an average value of the peak comparison value and generates the valley comparison value from the comparison value signal.

Abstract: A control device drives an operating current of a lighting unit formed with light emitting diodes. The lighting unit is connected to a contact pair of the control device. The control device sets at least one parameter of the operating current that depends on a diode type of the lighting unit. With the lighting unit switched off, the control device generates a measurement current and ascertains a measurement value to identify the diode type. A hysteretic regulator sets the parameter of the operating current, and a current source circuit sets a reference signal at a comparator during the operation of the lighting unit. With the lighting unit inactive, the current source circuit generates the measurement current. Alternatively, a precharge device of the control device charges an output capacitance at the contact pair by a predetermined precharge routine, and a deviation from a predetermined expected value is ascertained as the measurement value.

Abstract: A method for operating a DC-DC voltage converter, which, at an output, adjusts an output variable to a prescribed setpoint value by way of a regulator unit. Depending on an actual value of the output variable, the regulator unit sets a duty cycle of a pulse-width modulation. The regulator unit has an operating parameter for providing the pulse-width modulation. The operating parameter is variable and is changed to a new parameter value by a control apparatus which determines whether, with the unchanged setpoint value and the new parameter value, the regulator unit sets a lower duty cycle for adjusting the output variable than before the setting of the new parameter value. In that case, the new parameter value is retained. Otherwise it is changed back. The operating parameter that is varied by the new parameter value is a period of the pulse-width modulation and/or an edge steepness of switching edges.

Abstract: A driver circuit for a light-emitting diode arrangement has a supply terminal for connecting a voltage source. A boost converter inductance connects the supply terminal to a common circuit node. A switching unit connects the circuit node to ground depending on a switching signal. A rectifying unit connects the circuit node to an anode terminal for the light-emitting diode arrangement by way of a circuit branch to which a terminal of a storage capacitance and a terminal of an RC element are connected. A cathode terminal for the cathode side of the light-emitting diode arrangement is electrically connected to the circuit node. A buck converter inductance is connected in each case between the rectifying unit and the anode terminal and/or between the cathode terminal and the circuit node.

Abstract: A method for operating a DC-DC voltage converter, which, at an output, adjusts an output variable to a prescribed setpoint value by way of a regulator unit. Depending on an actual value of the output variable, the regulator unit sets a duty cycle of a pulse-width modulation. The regulator unit has an operating parameter for providing the pulse-width modulation. The operating parameter is variable and is changed to a new parameter value by a control apparatus which determines whether, with the unchanged setpoint value and the new parameter value, the regulator unit sets a lower duty cycle for adjusting the output variable than before the setting of the new parameter value. In that case, the new parameter value is retained. Otherwise it is changed back. The operating parameter that is varied by the new parameter value is a period of the pulse-width modulation and/or an edge steepness of switching edges.

Abstract: A control device drives an operating current of a lighting unit formed with light emitting diodes. The lighting unit is connected to a contact pair of the control device. The control device sets at least one parameter of the operating current that depends on a diode type of the lighting unit. With the lighting unit switched off, the control device generates a measurement current and ascertains a measurement value to identify the diode type. A hysteretic regulator sets the parameter of the operating current, and a current source circuit sets a reference signal at a comparator during the operation of the lighting unit. With the lighting unit inactive, the current source circuit generates the measurement current. Alternatively, a precharge device of the control device charges an output capacitance at the contact pair by a predetermined precharge routine, and a deviation from a predetermined expected value is ascertained as the measurement value.

Abstract: A method operates a DC-DC voltage converter. A current measurement circuit generates a current signal correlated with a coil current of a coil. A hysteretic switch control system electrically turns off a switch for driving the coil current, if the current signal signals a coil current greater than a peak comparison value, and electrically turns on the switch if the current signal signals a coil current lower than a valley comparison value. An actual value measurement circuit generates an actual value signal correlated with an electrical output variable of the DC-DC voltage converter. A controller unit adjusts the output variable to a prescribed setpoint value and, generates a comparison value signal depending on a control deviation and the switch control system sets an average value of the peak comparison value and generates the valley comparison value from the comparison value signal.

Abstract: A method for monitoring an AC voltage source, which is DC-decoupled from a reference potential and which generates an AC voltage between two AC voltage lines. Each of the AC voltage lines is coupled to the reference potential by way of a respective capacitive voltage divider and a respective component voltage signal is tapped at the voltage dividers and at least one root mean square value signal is generated therefrom and a check is carried out to determine whether the respective root mean square value signal meets a predetermined triggering criterion. When the triggering criterion is met, a fault signal is generated.

Abstract: The disclosure relates to a DC-DC converter in which a first coil terminal is connected with an input terminal and a second coil terminal is connected, on the one hand, via a rectification switch to an output terminal and, on the other hand, via a control switch to a ground potential and a control circuit is configured to switch in successive switching cycles in each case in a regulating phase the rectification switch to be electrically blocking and the control switch to be electrically conducting, and in a rectifying phase to switch the control switch to be electrically blocking. A measuring component generates a measurement signal which signals a current intensity of a coil current, and a comparator circuit compares the measurement signal with a threshold value and the control circuit keeps the rectification switch electrically blocking in the rectifying phase and conducts the coil current via a bypass diode if the current intensity was continuously lower than the threshold value in the regulating phase.

Abstract: A driver circuit for a light-emitting diode arrangement has a supply terminal for connecting a voltage source. A boost converter inductance connects the supply terminal to a common circuit node. A switching unit connects the circuit node to ground depending on a switching signal. A rectifying unit connects the circuit node to an anode terminal for the light-emitting diode arrangement by way of a circuit branch to which a terminal of a storage capacitance and a terminal of an RC element are connected. A cathode terminal for the cathode side of the light-emitting diode arrangement is electrically connected to the circuit node. A buck converter inductance is connected in each case between the rectifying unit and the anode terminal and/or between the cathode terminal and the circuit node.

Abstract: The disclosure relates to an electronic module comprising a source terminal for receiving an input current from an electrical voltage source and comprising an electrical input capacitance which is effective with respect to the source terminal, wherein the input capacitance is connected to the source terminal via a transistor circuit. The disclosure additionally provides that the transistor circuit is configured to conduct the input current via a respective switching path of at least one transistor, and a control device is configured to switch, during the switch-on process for limiting the input current, a control voltage at a respective control terminal of the at least one transistor, in a plurality of steps, from an off value at which each switching path is switched off, to a connection value at which a contact resistance of each switching path is minimized.

Abstract: A method and a device for the diagnosis of faulty light emitting diodes in a string (2) formed of at least two light emitting diodes. The light emitting diodes (3) are divided into at least two groups and an electrical measured variable is determined for each group with respective measurement units. Differences between the measured variable and a reference value are established per group and, by way of a diagnosis unit that is connected to the measurement units, a defect of a light emitting diode is identified on the basis of the ratio of the differences in the groups and signaled.

Abstract: The disclosure relates to a DC-DC converter in which a first coil terminal is connected with an input terminal and a second coil terminal is connected, on the one hand, via a rectification switch to an output terminal and, on the other hand, via a control switch to a ground potential and a control circuit is configured to switch in successive switching cycles in each case in a regulating phase the rectification switch to be electrically blocking and the control switch to be electrically conducting, and in a rectifying phase to switch the control switch to be electrically blocking. A measuring component generates a measurement signal which signals a current intensity of a coil current, and a comparator circuit compares the measurement signal with a threshold value and the control circuit keeps the rectification switch electrically blocking in the rectifying phase and conducts the coil current via a bypass diode if the current intensity was continuously lower than the threshold value in the regulating phase.

Abstract: A method for detecting a failure of at least one light emitting diode in a light emitting diode arrangement to which a supply current is applied by a constant-current source via a supply terminal and in which a respective luminous state of the light emitting diodes is set individually or in groups by means of a respective switching element by respective short-circuiting is disclosed, wherein a voltage signal of a chain voltage dropped across the light emitting diodes and dependent on the respective switching state of the switching elements is tapped off by a circuit apparatus at the supply terminal. The voltage signal is fed to an analog maximum value detector of the circuit apparatus, the maximum value detector is operated for a predetermined measurement duration and a maximum value signal of the voltage signal is provided at an output of the maximum value detector after the measurement duration.

Abstract: A method for detecting a failure of at least one light emitting diode in a light emitting diode arrangement to which a supply current is applied by a constant-current source via a supply terminal and in which a respective luminous state of the light emitting diodes is set individually or in groups by means of a respective switching element by respective short-circuiting is disclosed, wherein a voltage signal of a chain voltage dropped across the light emitting diodes and dependent on the respective switching state of the switching elements is tapped off by a circuit apparatus at the supply terminal. The voltage signal is fed to an analog maximum value detector of the circuit apparatus, the maximum value detector is operated for a predetermined measurement duration and a maximum value signal of the voltage signal is provided at an output of the maximum value detector after the measurement duration.