JAJSNK8D November 2021 – July 2022 TLC6984
PRODUCTION DATA
The LED open detection (LOD) function detects faults caused by an open circuit in any LED, or a short from OUTn to VLED with low impedance. This function was realized by comparing the OUTn voltage to the LOD detection threshold voltage level set by LODVTH_R/LODVTH_G/LODVTH_B (See FC3 for more details). If the OUTn voltage is higher than the programmed voltage, the corresponding output LOD bit is set to 1 to indicate an open LED. Otherwise, the output of that LOD bit is 0. LOD data output by the detection circuit are valid only during the OUTn turning on period.
Figure 8-8 shows the equivalent circuit of LED open detection.
The LED open detection function records the position of the open LED, which contains the scan line number and relevant channel number. The scan line order is stored LOD_LINE_WARN register (see FC16, FC17 for more details), and the channel number is latched into the internal 48-bit LOD data register (see FC20 for more details) at the end of each segment. Figure 8-9 shows the bit arrangement of the LOD data register.