The SI1027-B-GM is a RF Transceiver IC from Silicon Labs. It is a TxRx + MCU type with a frequency range of 240MHz to 960MHz and a protocol of EZRadioPro. The memory size is 16kB Flash and 4.4kB RAM. The power output is 13dBm (max) and the sensitivity is -121dBm. The data rate (max) is 256kbps. The RF family/standard is General ISM < 1GHz. The modulation types are FSK, GFSK, and OOK. The serial interfaces are I2C, SPI, and UART. The GPIO is 53. The current - receiving is 18.5mA and the current - transmitting is 17mA to 30mA. The voltage supply range is from 1.8V to 3.8V. The sensor is mounted using SMD (SMT) technology and is packaged in a 85-VFLGA Exposed Pad. The temperature range is from -40°C to 85°C.