Billions of Electronic Components on Chovm.com. Trade in Real Time, Logistics Service Optional,Thousands of Global Suppliers. SI4463-B1B-FMR, RF Receiver and Transmitter by Silicon Labs, IC RF TXRX+MCU ISM<1GHZ 20VFQFN. Package/CaseType is 20-VFQFN Exposed PadSurface Mount