The LP8555 datasheet recommends an inductance between 4,7uH and 6,3uH with 3,1A for most application. However in my application with L=4,7uH, i found a ratio between inductance peak to peak ripple current and mean inductance current of ΔiL(PP)/iL ≃ 240%. With this value the LP8555 must operate in DCM mode? do I have to increase the inductance value to operate in CCM mode?
Condition:
I’m using LP8555 for driving 2 string of 6 LEDS connected to bank A boost and 2 strings of 4 LEDs connected to bank B boost.
ILED max= 60mA (I connect two channels in parralel to reach 60 mA)
L=4,7uH, f=1Mhz
VIN=4.2V - 5.5V Vf(Schottky diode)=0,5V
VOUT1(max)=Vf_LED*(nb LED) =2,39*6=14,36V Iout1 (max) = 120 mA (BOOST bank A) 60mA/string LED
VOUT2(max)=Vf_LED*(nb LED)=2,39*6= 9,56V Iout2 (max) = 120 mA (BOOST bank B)
