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Compiler/LM3414HV: Lm3414 ic used for dimming of led light, problem of flicker we get in intensity of light while seen from camera

Part Number: LM3414HV
Other Parts Discussed in Thread: MSP430FR5729, LM3414

Tool/software: TI C/C++ Compiler

Hello Everyone,

                          Help me to slove my problem, i am using LM3414 IC to drive 12Watt LED Slim Light at 48v DC,  here in my project i am using controller msp430fr5729 to give dimmimg effect to led slim light and this led light is drive by IC LM3414 , now my problem is that i am giving moonlight dimming effect using controller's  timer PWM  which i get perfectly as per my requirement but the problem is that when i see the effect of  dimming on intensity of  light  in my moblie camera, i get black strip on led which is as shown below. so i want to remove this flicker from the light so what kind of changes i should do in my hardware or in my code so i can remove this black strip on light while seeing its effect on camera. The same Setup when i test on AC constant led driver by giving 230v i get perfect intensity of light when checked from camera, i does not get any black strip on light when check on camera.

here i am attatching the pictures of  flicker which i get in my mobile camera, when i had given PWM of 50 dutycycle to led light

here i am attatching the pictures of  flicker which i get in my mobile camera, when i had given PWM of 90 dutycycle to led light

i want to remove this black strip at every dutycycle i.e from 0  to 100 which i use for dimming purpose

Regards,

Kinjal

                         

  • Hello Kinjal,

    That is caused by aliasing due to the camera's refresh rate. This is a common issue and unfortunately the only good way to get rid of it is to change the dimming frequency so that it doesn't alias versus the camera refresh frequency. Using some output capacitance can help and may be worth a try, but it will likely just improve it and not get rid of it completely. Do you have flexibility to change the PWM dimming frequency?

    Regards,

    Clint