The AT6558R RF Transceiver IC QFN-40 RoHS is a radio frequency (RF) transceiver integrated circuit manufactured by Zhongkewei. It is a low-voltage, low-power consumption device designed for operation in the ISM (Industry, Science, and Medical) radio bands. The device supports transmission modes such as OOK, FSK, and GFSK. It has a range of up to 150 meters in open air and a data rate of up to 125Kbps. It is housed in a standard QFN-40 RoHS package and has an operating voltage of only 3.1V. It also has a built-in temperature sensor, low power operating modes, sleep modes, and wakeup modes. The AT6558R is ideal for applications such as wireless remote controls, smart meters, and building automation systems.