The CC2540 keyfob reference design is included in the CC2540DK-MINI development kit. Components in this design controlled by the CC2540 include a three axis accelerometer: buzzer (for alarm sounds): two color LED and two buttons. The design is used as a remote control in the CC2540 RC demo. The reference design demonstrates good techniques for CC2540 decoupling and RF layout. For optimum RF performance: these parts should be copied accurately. This is a 4-layer reference design with a discrete balun and a compact meandered inverted F PCB antenna. This antenna is the recommended small PCB antenna for the 2.4 GHz frequency band.