Is the Soft Start function of the LT3518 operates only at the initial start up, or it operates wch time the PWM wake up the driver?
So, if I am using the PWM input control, after each time the control stop the current throuth the inductor - the soft start will delay ramping of the current?
If positive- how to considet that , when I calculate the maximum frequency of the PWM?
I have to correct myself on this one. LT3518 will go to start up mode when Vfb goes below 1V.
When the PWM signal shuts off the LED current Vout is maintained which keeps LT3518 going to SS mode.
This means that it would only go to SS on initial power up.
To answer your last question, the maximum PWM frequency maintain a min off and on time of 1/6th of the switching frequency