For LCD, I have to make back-light voltage provision.
As per below image, LEDK1 to LEDK4 pins are internally grounded in LCD module itself.
But I have to add series resistor to limit current.
LED specification in LCD is as follows:
Is it good option to have common resistor to all LED's? What value should I choose if VF=3.2V (typ), IF-25 mA (max) for each LED.
What value of If should I consider to put it in below equation: Rs= Vs-Vf/(If)? Is it for single LED (25mA) or for 4 LED's (100mA)?