The EM92600/1C series are developed for 45/48 MHz of 10 channels band frequency of cordless telephone which is used in Mainland China. These devices are dual phase-locked loop frequency synthesizers contained ROM counters for receive and transmit loops with two independent phase detect circuits. A common reference oscillator and reference divider are share by the receive and transmit circuits. Other features include a lock detect circuit for the transmit loop, illegal code default, a buffered oscillator output for mixing purposes in the system, 5KHz tone output . The EM92601C is designed for easy MPU interface. It provides the same features as the EM92600C , but accepts channel programming via a clocked, serial input instead of parallel BCD inputs. The EM92600C is selected channels via machanical switches of parallel BCD input.