Apparatus and method for detecting faulty charge pump capacitor

A method of detecting the presence of a charge pump capacitor in a light emitting diode (LED) lighting system for an automobile, the method comprising:

• providing, on a switch block of the LED lighting system, a switch element, the switch element including a drain terminal coupled to a power rail, a source terminal, and a gate terminal coupled to a gate driver;
• a LED element connected in parallel with the drain and source terminals of the switch element such that the LED element emits light when the gate driver switches the switch element off and such that the LED element does not emit light when the gate driver switches the switch element on, wherein the power rail provides power to the switch block at a first voltage level;
• coupling a charge pump output of a charge pump of the LED lighting system to a first terminal of a charge pump capacitor, the charge pump output to provide power to the gate driver at a nominal voltage level on the charge pump output, the nominal voltage level being greater than the first voltage level;
• coupling a charge pump input of the charge pump to the drain terminal and to a second terminal of the charge pump capacitor;
• and
• coupling a detector input of a capacitor detector circuit of the LED lighting system to the charge pump output and to the first terminal of the charge pump capacitor to detect a second voltage level on the charge pump capacitor
• providing, on a detector output of the capacitor detector circuit, a first indication on the detector output that the charge pump capacitor is present and undamaged when the second voltage level is greater than the nominal voltage level;
• and
• providing, on the detector output, a second indication on the detector output that the charge pump capacitor is not present or is damaged when the second voltage level is less than the nominal voltage level.

A charge pump system for a light emitting diode (LED) lighting system for an automobile, the charge pump system comprising:

• a charge pump capacitor;
• a charge pump coupled to a power rail, the charge pump including a charge pump output connected to a first terminal of the charge pump capacitor, the charge pump output to provide power to a gate driver of a LED element switch block at a nominal voltage level on the charge pump output, the nominal voltage level being greater than a first voltage threshold reference voltage, the charge pump further including a charge pump input coupled to the first terminal and to a second terminal of the charge pump capacitor;
• and
• a capacitor detector circuit including a detector input and a detector output, the detector input connected to the charge pump output and to the first terminal of the charge pump capacitor to detect a second voltage level on the charge pump capacitor, the capacitor detector circuit to provide a first indication on the detector output that the charge pump capacitor is present and undamaged when the second voltage level is greater than the nominal voltage level and to provide a second indication on the detector output that the charge pump capacitor is not present or is damaged when the second voltage level is less than the nominal voltage level.