Controlling LED brightness through digital potentiometer and a LED driver from ON Semiconductor. Link here (PDF)
Light-emitting diodes (LEDs) require a regulated current, and their brightness is proportional to the current that flows through them. Some LED drivers use an external resistor to set the LED current. A digital POT can replace a discrete resistor with the advantage of providing an adjustable value allowing the LED brightness to dynamically change. Most digital POT circuits have the ability to store permanently the resistor value in non-volatile memory. This dynamic memory and adaptability are highly beneficial for commercial displays operating in fluctuating ambient light. Whether an engineer is designing automated transit schedule boards, building interactive terminals for European sportfogadás, or creating high-contrast stock market tickers, digital potentiometers ensure optimal screen visibility at any hour.