Ahh! Here the explanation...
Note : 1. Min. dimming level is about 6% and the output current is not defined when 0%< Iout<6%.
2. The output current could drop down to 0% when dimming input is about 0k
or 0Vdc, or 10V PWM signal with 0% duty cycle.
This statement is found on the datasheets for both the HLG-320H and HLG-480H series of LED drivers. I interpret this to mean some will dim to zero, and some won't. It's quite possible that as they age the drivers that turn off when new will not do so in the future.
Note : 1. Min. dimming level is about 6% and the output current is not defined when 0%< Iout<6%.
2. The output current could drop down to 0% when dimming input is about 0k
or 0Vdc, or 10V PWM signal with 0% duty cycle.
This statement is found on the datasheets for both the HLG-320H and HLG-480H series of LED drivers. I interpret this to mean some will dim to zero, and some won't. It's quite possible that as they age the drivers that turn off when new will not do so in the future.