Driving apparatus for a light emitting device and method for the same

A driving apparatus, comprising:

• a driving current source module configured to supply a current to a light emitting device via a node during operation;
• a protection module coupled to the node and the driving current source module and comprising:
• a current injection circuit configured to selectively inject the current into the node;
• a voltage detection circuit configured to selectively detect a voltage on the node;
• and
• a controller configured to selectively control a driving apparatus which includes the driving current source module, the current injection circuit and the driving current source module itself based on the detected voltage on the node;
• and
• a timing circuit configured to control time when the current injection circuit injects the current into the node;
• and
• wherein the controller comprises:
• a first comparator that selectively transmits a first comparator output to the current injection circuit and the timing circuit based on output of the voltage detection circuit and a reference voltage;
• and
• a second comparator that selectively outputs a second comparator output for disabling the driving current source module or the driving apparatus based on output of the voltage detection circuit and the reference voltage, said second comparator enabled by the output of the timing circuit.

An apparatus, comprising:

• a string of series connected light emitting diodes having an anode connection end and a cathode connection end;
• a drive transistor having a source-drain path connected in series with one of the anode connection end or cathode connection end at an intermediate node;
• wherein the series connected drive transistor and light emitting diodes are coupled between a first power supply node and a second power supply node;
• a current source configured to output a test current for application to said intermediate node;
• a control circuit configured to selectively control the drive transistor and the current source by:
• disabling the drive transistor, enabling the current source to inject the test current to the intermediate node, sense a voltage at the intermediate node in response to the injected test current, and selectively enable the drive transistor based of the sensed voltage.