Infineon Technologies Ag

Damiano Sartori

Marco Pamato

Maurizio Galvano

Franco Mignoli

Gernot Unterweger

Adolfo De Cicco

Fabrizio Cortigiani

Hans-Peter Kreuter

Enrico Tonazzo

Aurelio Pellegrini

Alfonso Nasciuti

Luca Mengani

Roberto Guerra

Christopher Gabriel

In some examples, this disclosure describes a light-emitting diode (LED) driver circuit configured to: control a set of LED channels; receive, from each LED channel of the set of LED channels, channel status information that indicates whether the respective LED channel is activated or deactivated; and determine, based on the channel status information corresponding to each LED channel of the set of LED channels, a channel status of the respective LED channel. Additionally, the LED driver circuit is configured to output, to a master computing device, the channel status corresponding to each LED channel of the set of LED channels; and output, to the master computing device, channel mapping information, wherein the master computing device is configured to determine, based on the channel status information and the channel mapping information, whether one or more error conditions are present in the set of LED channels.

Detecting error conditions in a plurality of LED channels

This disclosure includes systems, methods, and techniques for detecting one or more short connections in a plurality of light-emitting diode (LED) channels. For example, a circuit includes processing circuitry configured to control a plurality of driving devices in order to cause a pair of LED channels of the plurality of LED channels to operate in a first state during a first period of time and operate in a second state during a second period of time. Additionally, the processing circuitry is configured to compare a first electrical signal corresponding to the first state of the pair of LED channels and a second electrical signal corresponding to the second state of the pair of LED channels and determine, based on the comparison of the first electrical signal and the second electrical signal, if a short connection exists between the pair of LED channels.

Detecting short connections in a plurality of LED channels

A method and an electronic circuit are disclosed. The method includes detecting at least one operating parameter in an electronic circuit that includes a monitored LED string; adjusting a voltage threshold based on the at least one detected operating parameter; detecting a string voltage across the monitored LED string; comparing the string voltage with the voltage threshold; and detecting a defect in the LED string based on the comparing.

Method for detecting a defect in an LED string and electronic circuit with at least one LED string

An electronic circuit and a method are disclosed. The electronic circuit includes an LED circuit, wherein the LED circuit () includes: an input () configured to receive an input voltage (V); a drive circuit (A) connected to the input (); and an LED module (A) connected to the drive circuit (A) and comprising an LED string () with at least one LED. The drive circuit (A) is configured to monitor the LED module (A) for the occurrence of an LED short in the LED string () and to change from a normal mode to a defect mode upon detection of the LED short, and the drive circuit (A) is configured, in the defect mode, to operate the LED string () in at least one defect cycle that includes deactivating the LED string () for a deactivation period, activating the LED string for an activation period, and checking for the persistence of the LED short in the activation period.

Electronic circuit with an LED module

The disclosure is directed to a circuit that may detect a single short in a chain of loads, such as light emitting diodes (LEDs). The circuit may drive either multiple LED chains or a single LED chain to determine whether one, or more, of the LEDs in the LED chain is no longer working because of a short. The circuit determines whether the LED chain voltage satisfies a threshold based on a single LED voltage drop. Therefore, the same circuit may be used for applications regardless of the number of LEDs in an LED chain. Additionally, the circuit, according to the techniques of this disclosure may use may use no output pins, other than those used to deliver current to LED chains, regardless of the number of LED chains that the circuit drives.

Detection of single short-LED in LED chains

An embodiment method for short-circuit detection includes determining a set of local reference voltages each associated with a respective load chain in a plurality of load chains, and determining a global reference voltage in accordance with the set of local reference voltages. The method also includes determining, for each load chain in the plurality of load chains, a respective per-chain reference voltage in accordance with the global reference voltage, and comparing, for each load chain in the plurality of load chains, the respective per-chain reference voltage relative to a respective measured voltage across each load chain to determine a respective short-circuit condition.

System and method for short-circuit detection in load chains

A method and circuit are described in which a maximum voltage is determined from among a plurality of series load voltages, where each series load voltage of the plurality of series load voltages is a voltage defined by a corresponding series of N loads of a plurality of series of N loads, where N is an integer greater than one. Also, a minimum voltage may be determined from among the plurality of series load voltages. Next, the maximum voltage from among the plurality of series load voltages may be compared with the minimum voltage from among the plurality of series load voltages to make a determination as to whether the maximum voltage from among the plurality of series load voltages exceeds the minimum from among the plurality of series load voltages by a threshold voltage. Then, an indication can be output based on the results of the determination.

Single LED short detection in multichannel LED

During a start-up phase, each corresponding test current is delivered to a corresponding chain of loads of a plurality of chain of loads. Each chain of loads is coupled between a common node and a corresponding output node. Each chain of loads includes N series-coupled loads, where N is an integer greater than one. A maximum voltage is determined from among the output voltages, where the output voltages are the voltages at the output nodes. Also, a minimum voltage is determined from among the output voltages. The maximum voltage from among the output voltages is compared with the minimum voltage from among the output voltages to make a determination as to whether the maximum voltage exceeds the minimum voltage by a threshold. An indication is output based on a result of the determination.

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Padua, Italy

Damiano Sartori