LED power and drive damage is caused by an overvoltage […]
LED power and drive damage is caused by an overvoltage (EOS) on the input supply and a true open-circuit load fault. In addition to causing the weld line to blow out, it may also cause damage to other parts near the weld line, such as sealing material. For LED lighting in automobiles, the transient surge load of ISO7637-2 is an important threat to its normal operation. This damage is usually caused by a large transient overcurrent. LED lighting has made great progress in the field of application, high-power white LED as a new green lighting technology, high light conversion efficiency, low energy consumption, long life, no maintenance and other advantages, gradually being used in various lighting. These events are transient and have very short durations, which we typically refer to as spikes, such as "current spikes" and "voltage spikes." Over-current impact of the input power often results in damage to the driver chip in the driver circuit and breakdown of the passives such as the capacitor.
First, LED lighting damage from the power and drive failure, the second is from the LED device itself failure. Transient overcurrent events refer to the current flowing through the LED exceeds the maximum rated current in the LED datasheet, which may be due to high current directly or indirectly generated by high voltage, such as transient lightning strike, instantaneous switching power supply State switching noise, power grid fluctuations caused by over-current events. These damage can be manifested as an immediate failure of the device, it may also occur long after the overcurrent impact failure, shorten the LED life.
If the load is short-circuited, the overcurrent of the driving circuit may be driven. The driving circuit may be damaged by short circuit or overheat caused by short-circuit. LED's long life is based on its safe working environment, for LED lighting, there are two main threats to its life: First, over-impact, that is, the LED current exceeds the maximum rated current in the LED datasheet , Including over-voltage caused by over-voltage impact; the other is overheating damage. Electrostatic Discharge (ESD) damage is one of the most common transient overvoltage hazards in the manufacture, transport and application of highly integrated semiconductor devices today, and LED lighting systems must meet the IEC61000-4-2 standard "Human Electrostatic Discharge Mode" 8kV Contact Discharge to Prevent System from Overvoltage Impairment Caused by Electrostatic Discharge When the LED is over-impacted, the failure mode is not fixed, but it usually results in damage to the soldering wire. The transient over-current event also includes LED Turn on the power, or transient over-current at live insertion and removal.