SNVSCE3B May 2023 – November 2023 LP5866T
PRODUCTION DATA
The LP5866T includes LED open detection (LOD) for the fault caused by any opened LED dot. The threshold for LED open is 0.25V typical. LED open detection is only performed when PWM ≥ 25 (Mode 1 and Mode 2) or PWM ≥ 6400 (Mode 3) and voltage on CSn is detected lower than open threshold for continuously 4 sub-periods.
Figure 7-11 shows the detection circuit of LOD function. When open fault is detected, 'Global_LOD' bit in Fault_state register is set to 1 and detailed fault state for each LED is also monitored in register Dot_lodx (x = 0, 1, … , 17). All open fault indicator bits can be cleared by setting LOD_clear = 0Fh after the open condition is removed.
LOD removal function can be enabled by setting 'LOD_removal' bit in Dev_config2 register to 1. This function turns off the current sink of the open channel when scanning to the line where the opened LED is included.