What reason is chip of full-color led display screen smoke burns out

Time:2018-12-29 Views:38

LED display as an electronic product, in the ordinary use of the process of some fault is inevitable.LED displays have integrated circuits and chips, integrated circuit chips appear smoke burning phenomenon is a common fault.Full color led display chip smoke burning is what reason, the following small make up to give you a detailed way to come.

1. Negative and positive connection of power supply: in accordance with the standard design of electronic products, the power supply terminal position will be marked with "VCC" and "GND" (or "+", "-"), which respectively represent the wiring position of the positive pole and the negative pole.But for the lack of basic knowledge of electrical and electronic operators, it is possible to connect the positive and negative poles of the power supply due to unconscious, even qualified technicians may also make operational mistakes.Inverting the positive and negative electrodes of a power supply often results in smoke burning of most constant current/constant voltage drive chips on the module.

2. Abnormal control signal: it is common for a line of normally bright and highlighted faults to appear on full-color led display screen, which is often caused by abnormal wiring contact or error in debugging parameters.Strictly speaking, well-designed LED display products should have protection circuit to avoid high brightness.For products without protective circuit, if the line high brightness is always bright, if not excluded in time, the line drive chip of the module (such as 4953) may be sharply increased in temperature due to continuous high current operation and eventually burn out.Of course, compared with the previous products, the on-load power consumption of the current industry‘s full-color led display module is relatively low (below 2A), and the maximum operating current of most of the line drive chips is around 3A. The possibility of smoke burning of the line drive chip caused by the constant brightness of the line in the module is relatively small.As a result, most products on the market no longer design protective circuits.

Iii. High power supply voltage: the rated working voltage of LED display module is usually 4.5v-5v, the maximum working voltage of integrated chip on the module is generally not higher than 7V, and the maximum reverse voltage of LED lamp tube is also below 7V.Therefore, the power supply voltage above 7V can damage the integrated chip and LED lamp tube.When the voltage reaches about 9V, conventional constant current/constant voltage drive chips often start to heat up sharply and may emit smoke.Under normal circumstances, when the voltage is 10-11v, the chip will burn down to varying degrees after being powered on for about 2 seconds.The LED display is powered by a constant voltage switch with an output voltage of 5V, so the possibility of overvoltage is not very great.Even if the control circuit of the switching power supply fails, the possibility that the output voltage is abnormal and reaches more than 9V is extremely small (does not mean that it is impossible!)..It is worth mentioning that some poor switching power supply, high output voltage ripple even if it cannot cause chip smoke burn down, or enough to cause chip function failure.

Conclusion: in practical application, the cause of chip smoke burning is mostly positive and negative pole connection, followed by abnormal control signal, but this situation will be more and more rare, and finally is a very small number of power supply overvoltage.Some of these faults are caused by human, whether LED display manufacturers or end users, in order to reduce the occurrence of full-color LED display chip faults, it is necessary to improve the technical level of operators.