The Realtek RTL8761ATV-CG is a highly integrated single-chip Bluetooth 2.1/3.0/4.0 controller with a UART interface. It combines a BT Protocol Stack (LM, LL, and LE), BT Baseband, modem, and BT RF in a single chip.
The RTL8761ATV Bluetooth controller is compatible with Bluetooth core specification v4.0, and supports dual mode (BR/EDR + AMP + Low Energy Controllers). It is compatible with previous versions, including v2.1 + EDR and v3.0 + HS. For BR/EDR, it supports scatternet topology and allows active links in slave mode and master mode. For Low Energy, it supports multiple states and allows active links in master mode. The links in BR/EDR and LE can be active simultaneously.