I have a prototype board made here using the MP3398A as a boost converter for 4 strings, 7 led’s 2.9 forward voltage per LED at 350mA. Vin is 12V and I am measuring 20V at Vout which is good. However, with ADIM and PWM high (100% duty cycle) I am only measuring .034A going in and out of the LED strings which is about 10% of what I would expect. Additionally with low duty cycles the current is even lower and the LEDs are flickering but the voltage appears to remain okay at 20V on Vout… Any thoughts on why this may be?
Thanks,
Mike D.