Damage to the power supply IC is often caused by overstress of the input voltage, which occurs when the hot insertion of the power supply causes an excessively high voltage spike or when the resonance is formed by the line inductance and low ESR ceramic capacitor.
There will always be some IC damage in the process of our project development and product mass production, and it is usually not always easy to find the root cause of these IC damage. The difficulty is even greater when occasional damage is difficult to reproduce. And sometimes the IC failure performance is simply destructive, IC may have been burned in a mess, even if the original IC analysis, often can not find the root cause of failure, this situation, as an engineer you estimate the scalp to feel bursts of numbness.
The reason is caused by excessive voltage, in life, if you find that the IC of your air conditioning board is burned out, which means that your voltage is unstable, and often expands, then in the case of excessive voltage, its heat consumption will be greater, this part of the heat will cause the IC worker to burn out
IC series high voltage, or output short circuit phenomenon, working environment temperature is too high, are easy to damage