ON Semiconductor has introduced the NCP1840, a multi-LED driver which can drive up to eight LEDs independently, using any illumination pattern created by the user. The driver is suitable for multi-LED indicators that communicate status and diagnostic conditions. Current and dimming level programming is done by writing to and reading registers via a serial interface that uniformly controls the brightness and blink rate of each LED. LED brightness levels can be controlled logarithmically - rather than linearly - to accommodate natural eye viewing with no brightness distortion. According to the company, the LED driver is suitable for portable applications as it extends battery life by using a high efficiency, low noise, quad-mode charge pump. The charge pump and constant current regulators maintain forward LED voltage and active operation despite swings in input voltage. The driver requires five small ceramic capacitors and one resistor to form a complete LED power supply and current controller. The LED driver is suitable for the industrial, computing and consumer end markets. It is available in a Pb-free, RoHS-compliant, 4x4mm QFN-20 package, and operates between -40 and +85°C.
