PWM dimming frequency is 200Hz.
I change duty cycle from 10% to 1% with 10 steps equally separated, such as 10%, 9%, 8%,.....1%, within 3s.
It looks flickering in the run, maybe especially at the middle of this run.
What may happen? jitter of duty cycle, or overshoot of current in LED?
Ok your dimming period is 5ms
The on time for 5% is 250us.
Is your led driver capable of getting back up to regulation level in 250us?
Is it a hysteretic led driver.
Does it have a frequency compensated feedback loop?……if so it might be slower unless you have a controller which “freezes” the error voltage during the pwm off times…and hopefully you have a series fet to switch the leds totally off during the dead time, so that there is no need for the feedback loop to get back up into regulation when the leds come back on.
But yes the low duties often cause problems……and your strange current variation looks odd.
doe it look like flickering when you go from say 55% to 50%?
Undervoltage lockout being tickled by weak mains,
poor socket connection or a PFC front end problem?
Thermal protection toggling due to a die or board level
heat issue?
Control loop instability?
Noise issue w/ current mode control at low duty cycles
is often a problem, with the turnoff edge coming close
to turnon the switch "ringing tail" may not have
quenched and can make multimodal pulse widths?