Analysis on the distribution and trend of control signals on the LED display unit board

Figure 1: Back view of unit board

Unit Board Chip Analysis Description

1. The red chip in the figure is the HC245 chip, which plays the role of signal amplification. Chip 1 amplifies the signal of the upper half of the unit board, that is, the first and second groups of RGB data. Chip 2 amplifies the signal of the lower half of the unit board, that is, the third and fourth groups of RGB data. Chip 3 amplifies the ABCD line signal, CLK signal, SC latch signal, and OE control signal. Chip 4 amplifies all signals and sends them to the unit board output interface .

2. The blue in the picture is the driver chip of the LED light , which can be TB62726, MBI5024 and other chips. The main function is to control the column display on the control unit board . The TB62726 in the picture, the 1st and 4th columns of blue control the red light, the 2nd and 5th columns of blue control the green light, and the 3rd and 6th columns control the blue light. One TB62726 controls 16 columns, and a group has 3 TB62726s, corresponding to the 3 types of red, green and blue LED lights.

3. The green chip in the figure is 4953. Its main function is to control the row display on the unit board. One 4953 controls 2 rows, and 8 control 16 rows.

Signal trend analysis

1. CLK signal, SC latch signal, OE control signal direction: input - enter the red chip 3 and chip 4 at the same time - enter chip 2 and chip 1 at the same time - connected in parallel to each TB62726 chip.

2. Signal direction of rows ABCD: Input—enters red chip 3 and chip 4 at the same time—chip 3 output is connected to 4 green 4953 chips, and chip 4 output is connected to 4 green 4953 chips.

3. RGB data signal direction: Input—the first and second groups of RGB data enter chip 1, and the third and fourth groups of RGB data enter chip 2—in the first group of RGB data, R1 data enters the blue chip 1 and chip 4 in series; G1 data enters the blue chip 2 and chip 5 in series. B1 data enters the blue chip 3 and chip 6 in series. The same goes for other groups of RGB data.

Figure 2 Interface definition diagram