SINGLE LED FAILURE DETECTION IN A LED CHAIN

摘要

Methods and circuits are described in which an SLS driver circuit includes an SLS driver current source that may be arranged to provide an SLS current to a series SLS chain at a series SLS node. The series SLS chain may include a plurality of SLSs connected in series. The SLS driver circuit also includes a diagnostic current source that is arranged to provide a diagnostic current to a diagnostic resistor at a diagnostic resistor node. The series SLS chain also includes a comparison circuit that may be arranged to compare a series SLS voltage at the series SLS node with a diagnostic voltage at the diagnostic resistor node, and to output a status signal based on a result of the comparison such that the status signal is based, at least in part, on whether a failure condition exists in the series SLS chain.

主权项

1. A device, comprising:
a semiconductor light source (SLS) driver circuit, including:
an SLS driver current source that is arranged to provide an SLS current to a series SLS chain at a series SLS node, wherein the series SLS chain includes a plurality of SLSs connected in series;a diagnostic current source that is arranged to provide a diagnostic current to a diagnostic resistor at a diagnostic resistor node; anda comparison circuit that is arranged to perform a comparison to compare a series SLS voltage at the series SLS node with a diagnostic voltage at the diagnostic resistor node, and to output a status signal based on a result of at least the comparison such that the status signal is based, at least in part, on whether a failure condition exists in the series SLS chain.