I have an AFY480272A0-4.3INTH TFT LCD and I'm confused about how to control the backlight using PWM. After googling it, I found this similar problem.
Here are my backlight LED characteristics:
After I read the similar problem, I drew some circuit schematics. I am still confused about some parameters.
Questions:
- Can I control the backlight like the picture above? I'm using an IRLML2803 MOSFET that has drain-source voltage of 30 V.
- Is my R1 value right? I did some LED calculations in https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-led-series-resistor with LED forward voltage 18 V, forward current 40 mA and supply voltage 24 V.
- What is the value of R2?