Highly integrated, UHF ASK/FSK, multi-channel, half-duplex transceiver with low power consumption in a small 7 by 7-mm QFN48 package. The receive part is built as a fully integrated low-IF receiver. FSK transmission and ASK transmission switching of the power amplifier both use direct PLL modulation with the fractional-N synthesizer.This device supports data rates of 1Kb/s to 20Kb/s (FSK) and 1Kb/s to 10Kb/s (ASK) in Manchester mode and bi-phase mode, plus other codes in transparent mode. It can be used in either the 431.5MHz to 436.5MHz or 862MHz to 872MHz bands. Very high system integration results in the need for only a small number of external components.Its remote control unit does not require a bulky blocking SAW due to its blocking and selectivity performance, an additional 15 to 20-dB loss, and the narrow bandwidth of a typical loop antenna. Both base and mobile station sides fully integrate the building blocks they need for typical remote control and access control systems.