I am designing a PCB for a university project that will include an LCD display which is powered by 3.3VDC regulated supply. Unfortunately this display has backlight LEDs in series that have total forward voltage of 6.4 volts. My board includes 3.3VDC and 5VDC regulated power supplies which unfortunately cannot satisfy the required 6.4VDC. I am hesitating if I can use my 24VDC unregulated power supply for this purpose. The power supply would have a 2 volts voltage ripple(100Hz) with a max. peak of around 24 volts. I was thinking if it would be viable to put a resistor in series and supply the Display LEDs with this PSU.
- Is this unregulated voltage going to present a problem for the display LEDs or the display in general?
- Will the voltage ripple be visible through the LCD display brightness?
- Do you have an advice for a better approach considering the above mentioned PSUs?