RJ45 connector, as a widely used network connector, plays an important role in the field of network communication. In addition to transmitting data, many RJ45 connectors have integrated LED lights to indicate network status and data transmission. Therefore, when designing the LED lamp current of the RJ45 connector, special attention needs to be paid to the following points to ensure the normal operation of the LED lamp and extend its service life.

First, understand the basic characteristics of LED lights:

The LED lamp is a semiconductor device whose operating current and voltage have a significant impact on performance and life. In general, the rated working current of the LED is about 20 MA, and the recommended working voltage is 3.0-3.5V. However, in practical applications, due to fluctuations in ambient temperature and power supply voltage, the operating current of the LED may deviate from its rating, thus affecting its performance and life.

Second, reasonable design of LED lamp current:

1. Choose the right power supply:

When designing the LED light circuit of the RJ45 connector, the appropriate power supply should be selected first. The output voltage and current of the power supply should match the rating of the LED to ensure that the LED is operating within its normal operating range. If the power supply output voltage is too high or the current is too large, it may cause the LED to overheat and shorten its service life.

2. Use constant current source driver:

Due to the steep current-voltage characteristic curve of leds, small voltage changes can lead to large current fluctuations. Therefore, it is recommended to use a constant current source to drive the LED lamp to ensure that its operating current is stable. The constant current source can automatically adjust the output voltage when the ambient temperature and power supply voltage change, and keep the working current of the LED constant.

3. Control current accuracy:

When designing the constant current source, the current accuracy should be controlled within a reasonable range. In general, the current accuracy requirement is within ±3% to meet most application requirements. Excessive accuracy requirements will increase the cost, and the performance of the LED has little impact.

Third, pay attention to the wiring mode of LED lights:

1. Avoid the same color LED lighting at the same time:

In some RJ45 connectors, LED lights may be designed in parallel forward and reverse to accommodate different power connections. In this case, it should be avoided to light the LED of the same color at the same time to prevent the LED from being damaged by too much current. When designing the schematic, ensure that the power pins of the two leds are connected to different voltage sources.

2. Correct LED connection:

For standard LED connections, LED+ should be connected to the positive side of the power supply, and LED- should be connected to the negative side of the power supply, with appropriate current limiting resistors in series to prevent excessive current. The resistance value of the current limiting resistor should be calculated according to the rated current and power supply voltage of the LED to ensure that the LED operates within the normal operating range.

Fourth, consider the impact of environmental factors on LED lights:

1. Temperature effect:

The current and voltage characteristics of leds are greatly affected by temperature. When the temperature rises, the current and voltage of the LED will rise. Therefore, the heat dissipation problem should be considered in the design to ensure that the LED will not produce too high temperature during the working process. At the same time, it is also possible to automatically adjust the working current of the LED by designing a temperature compensation circuit to adapt to changes in the ambient temperature.

2. Power supply voltage fluctuation:

Fluctuations in the power supply voltage may also affect the operating current of the LED. Therefore, the voltage regulator circuit or power filter circuit should be used in the design to reduce the impact of power supply voltage fluctuations on the LED.

Summary: When designing the LED lamp current of the RJ45 connector, it is necessary to comprehensively consider the basic characteristics of the LED, power supply selection, constant current source driver, wiring mode and environmental factors. Through reasonable current design and effective protection measures, you can ensure the normal work of LED lights and extend their service life. At the same time, it will also help improve the stability and reliability of the entire network system.