SLVSEJ1A February 2021 – May 2022 TLC6983
PRODUCTION DATA
Figure 8-12 shows the LSD caterpillar issue caused by short LED. Suppose the LED0-1 is a short LED. When it scans to the line1 and the OUT1 is turned off, the OUT1 voltage is the same with scan line0 voltage because of the short path of the LED0-1. At this time, there is a current path from the line0 to the GND through the LED1-1 and SW1-1, which causes LED1-1 light to be unwanted.
The TLC6983 device implements internal circuits that can eliminate the caterpillar issue by short LEDs. As is shown in Figure 8-12, the LED short caterpillar is caused by the voltage of the Vclamp on the line, so it can be solved by adjusting the LSD_RM (see FC3 for more details) to let the voltage drop of the LED1-1 be smaller than LED forward voltage.