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.