Full color LED display chips burn out the cause of dialysis
LED display as an electronic product, in the normal course of the use of some faults is inevitable. There are integrated circuits and chips on the LED display. The phenomenon of burning and burning of integrated circuit chips is a common failure. Full-color LED display chip smoke what is the reason?
First, the power positive and negative reversed: According to the standard design of electronic products, the power terminal position will have a "VCC" and "GND" logo (or "+", "-"), respectively, that the positive and negative wiring location . However, for operators who lack the basic knowledge of electrotechnics and electronics, it is still possible to invert the polarity of the power supply unconsciously, and even qualified technicians may operate mistakes. Positive and negative power supply will often lead to reverse the module most of the constant current / constant voltage driver chip smoke burned.
Second, the control signal is abnormal: full-color LED display line and highlight the phenomenon of the line is also very common, often due to abnormal cable or debugging parameters caused by error. Strictly speaking, well-designed LED display products should have to avoid highlighting the protection circuit. Without protection circuit products, the line appears bright, if not ruled out in time, the module's line driver chip (such as 4953) may be due to sustained high current work temperature rose sharply finally burned. Of course, compared with the previous products, the industry's full-color LED display module, the line driver chip with a relatively low power consumption (2A below), and most of the line driver chip maximum operating current of about 3A, Module due to the emergence of a line of light led to row drive chip is less likely to burn smoke. As a result, most products on the market are no longer designed to protect the circuit.
Third, the power supply voltage is too large: LED display module rated voltage is usually 4.5V-5V, the maximum integrated module chip operating voltage is generally not higher than 7V, LED lamp maximum reverse voltage Below 7V. Therefore, more than 7V supply voltage, you can damage the integrated chip and LED lamp. When the voltage reaches about 9V, the conventional constant current / constant voltage driver chip will often start a rapid fever and may smoke. Under normal circumstances, the voltage at 10-11V, continuous power 2 seconds or so, the chip will be burned to varying degrees. As the LED display using the output voltage of 5V constant-voltage switching power supply, so the possibility of over-voltage and not great. Even if the switching power supply control circuit fails, the possibility of its output voltage anomalies and reach more than 9V is also minimal (not impossible!). It is worth mentioning that some of the inferior switching power supply, high output voltage ripple even if the chip can not cause smoke burned, or enough to cause the chip function failure.
Summary: In practical applications, most of the causes of chip smoke are reverse polarity, followed by control signal abnormalities, but this situation will be less and less common, and finally a very small number of supply over-voltage conditions. Some of these failures are man-made, whether it is LED display manufacturers or end-users, in order to reduce the occurrence of full-color LED display chip failure, improve the technical level of the operator is very necessary.
