Hi all,
I'm working on a Board where we have 16 circuits with LM3414HV. Each circuit
is dirivng 3 LEDs the Input Voltage is 12V.
L1 is 100µH
ILED is 0.5A
D1 is 2A Vf 0.56V
I have tried 450 kHz for fsw what was aweful, afterwards I've tried to use a single frequency for every chanel between 330 - 450 kHz what makes
it better.
For Cin I've used 10µF in the begining and also tried now after frequency changing above to use a 4.7µF and a 2.2µF capacitor.
The used PWM for dimming is 2kHz fix.
My problem is that I have a randomized flash on a single circuit when dimming down at a low end of about 4 to 5 % PWM its really randomizing
and most times its just one channel at one time.
Any ideas how to get rid of this issue?
Thanks in advance.