LED lamp failure analysis and circuit protection

- Jul 16, 2018-

LED lamp failure is caused by the failure of power supply and drive, and the second is from LED device.

Its own failure. Often the damage to the LED power supply and drive comes from the overcurrent surge (EOS) of the power supply and the open circuit fault at the load. The over-current shock of the input power source often causes damage to the driver chip in the drive circuit. The failure of the LED device itself is mainly due to the following conditions:

Transient overcurrent event

Transient overcurrent events mean that the current flowing through the LED exceeds the maximum current in the LED technical data sheet. This may be due to direct current generation or high voltage indirect generation, such as transient lightning strikes, switching power supply transients. State switch noise, overcurrent caused by overvoltage events such as grid fluctuations.

These events are transient and have a very short duration. Usually we call them spikes such as “current spikes” and “voltage spikes”. The transient overcurrent event also includes the LED being powered on or the transient overcurrent when plugged in.

For LED lighting in automobiles, the failure mode of the transient load dump surge of ISO7637-2 is not fixed, but usually leads to damage to the weld line. This damage is usually caused by extreme transient overcurrents, which can cause damage to other parts of the weld line, such as sealing materials, in addition to causing the weld line to blow.