An earlier slide showed a single LED implementation where the TXO signal was used to directly control a single LED. Here is another application example where the Si1120 is used, in conjunction with an MCU, to control three IR LEDs which may be useful for motion, position sensing (XYZ) or other similar functions (IR sliders). Each LED is gated through an external gate that is enabled on a time multiplexed fashion by the MCU. For example, in the figure, the P2.1 signal, when high, enables the TXO signal to sink current from the D1 LED through Q1. The other two GPIOs shown (P2.2 and P2.3) would leave those gates disabled while the D1 LED is used. On the next cycle the P2.1 I/O is de-asserted and the P2.2 I/O is asserted causing the TXO signal to sink current through the LED connected to Q2. This cycle repeats for the remaining gates and diodes in the system. The Si1120EK includes a board that implements this three LED scheme and this schematic is a representation of that system.