The CC2650EM-4XS_Ext_Reg reference design contains schematics and layout files for the CC2650 configured for external regulator operation using the TPS62740 DCDC converter. The reference design demonstrates good techniques for CC2650 decoupling and RF layout. For optimum RF performance, the reference design, both schematic and layout, should be copied accurately. There are several reference designs to choose from for the CC26xx device family, including designs with the various package types and also the different RF front-end options. All of the reference designs are with 2-layer PCB and has on-board PCB antenna.