The transmit side of the one-way link is the Si4010. This integrated transmitter, MCU, and oscillator is a highly integrated sub-GHz wireless product and is included in most Si4355 demo kits. The only external components needed for many applications are a single capacitor, along with the battery and any LEDs or buttons that are desired. The full integration of the whole transmit circuit into one chip not only makes the Si4010 easy to use but also provides a low cost, small solution. The Si4010 allows for long battery life by providing low shutdown current. Its simple application, high performance and low cost, along with its flexibility has made the Si4010 a very popular product.