I was wondering if my display backlight could be driven by a voltage of 5 V. The datasheet (see image) says that it only needs a current of 60mA so could I put in 5 V and a 80 Ω resistor to make the brightness doable?


I tried with 16 V and a 330 Ω resistor and that made the backlight visible. The datasheet specifies 17 V minimum and it made me question things.


No, the backlight is six white LEDs in series. 5V is not enough to overcome the sum of diode threshold voltages so it won't work.

It is possible to buy LCD displays where the LEDs are in parallel and these can be powered from 5V. However series connection is more common since there are plenty of low cost boost ICs you can get to drive them, and these will allow operation from a wide range of supply voltages and incorporate PWM and current regulation brightness control (not always easy to get right, especially if you are worried about colour balance).

  • \$\begingroup\$ Thanks for the great answer. Planned to have it battery powered with a ~6.3V li ion battery but I will look for other options. \$\endgroup\$ – Cesar Hanshoff Oct 13 '18 at 13:53
  • \$\begingroup\$ @CesarHanshoff Just search for "white led backlight driver". There are a huge number of ICs around and they are all pretty easy to use (usually one external inductor and a couple capacitors). \$\endgroup\$ – Jon Oct 13 '18 at 14:01
  • \$\begingroup\$ Thanks, I didn't know those ICs existed that amplify voltage for LCDs. I couldn't grasp how some mobile devices with tiny batteries could run. \$\endgroup\$ – Cesar Hanshoff Oct 13 '18 at 14:59

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