LEDs bring a new dimension to displays, appliances, automotive lighting and other consumer devices. Color and light are an integral part of the user interface for conveying information, draw attention, or simply provide eye-pleasing visual effects. LEDs can create a wide range of possible colors and brightness levels by turning on/off the Red, Green and Blue LEDs at different proportions. Since LEDs are current controlled semiconductor devices, LED drivers must include constant current sources. These current sources are programmed and updated by an external microcontroller in order to achieve colorful visual effects. There are two LED driver architectures, multi-channel and matrix; both programmable via an I2C interface bus. The multi-channel drivers are meant for applications requiring a small number of LEDs being driven at high current while matrix drivers shine when driving a large number of LEDs in a limited PCB area. Matrix drivers have both sink and source current blocks referred to as Row and Column as shown here in the diagram. The remainder of this presentation will discuss the implementation of matrix LED drivers.