The Magic LED Light in Chip Testing

Date：2024-03-08 16:42:09Views：1

With the rapid development of LED lighting technology, the performance indicators of LED lighting products such as stability, service life, intelligence, display, and light efficiency are becoming increasingly mature, meeting market demand. LED lighting products no longer only meet general lighting needs, but also derive various application fields according to different application scenarios, and the market scope continues to expand and extend. With the continuous maturity of technology and further price reduction, LED lighting products have gradually penetrated into many fields such as home lighting and industrial lighting in recent years, forming a huge potential application market. In the future, with the development of segmented industries such as landscape lighting and automotive lighting, the demand for LED lighting market will continue to grow rapidly.

Recently, we received a customer's inspection of an intelligent external control integrated LED light source (model: WS2812B). Let's share the "magic" of intelligent LED lights with everyone through functional testing.

WS2812B is an intelligent external LED light source that integrates control circuits and light-emitting circuits. It has a smaller volume and the external dimensions are the same as 3535LED beads, with each component being a pixel.

The data protocol adopts a single line return to zero code communication method. After the pixel is powered on and reset, the DIN end receives the data transmitted from the controller. The first 24 bit data sent is extracted by the first pixel and sent to the internal data latch of the pixel. The remaining data is shaped and amplified by the internal shaping processing circuit and then forwarded to the next cascaded pixel through the DO port. After each pixel transmission, The signal is reduced by 24 bits.

From the above information, it can be understood that:

1. The combination of T0H high level and TOL low level forms "0 code", while the combination of T1H high level and T1L low level forms "1 code". The high/low level time must be strictly set according to the specifications.

2. LED lights can be cascaded by first locking the first 24 bit data pixel sent to the internal data latch, and the remaining data is transmitted and locked to the next LED light through the DO port in the same way.

3.24 bit data structure: green light (G0-G7), red light (R0-R7), blue light (B0-B7).

After understanding the working principle of LED lights, let's use a professional functional testing machine to verify. Firstly, according to the specifications, the testing conditions can be set (VDD=5V, VIH=3.5V, VIL=1.5V), and the time parameters are set as follows:

Test interface:

Test results:

LED lighting effect:

In this test, we verified the display effect of the three primary colors (red, green, and blue) and the correctness of cascading data transmission. However, this LED can achieve 256 levels of brightness display and can achieve full color display of 16777216 colors. In terms of electrical parameters, the power supply voltage, power supply current, high level input, low level input and other parameters have been verified. If you want to know more about LED lamp testing, you can follow the official WeChat official account and send us a private message!