The MC33410 Dual CVSD/Cordless Phone system is designed to fit the requirements of a 900 MHz digital cordless telephone system. The device c o n t a i n s a C V S D ( C o n t i n u o u s l y Va r i a b l e S l o p e D e l t a Modulator/Demodulator) Encoder to digitize the speech for the RF transmission, and a CVSD Decoder to reconstruct the received digital speech from the RF receiver. Provisions are made to transmit and receive data as well. Included are three PLLs (PhaseLocked Loops). Two are intended for use with external VCOs and 64/65 or 128/129 dual modulus prescalers, and can control the transmit and receive (LO1) frequencies for the 900 MHz communication. The third PLL is configured as the 2nd local oscillator (LO2), and is functional to 80 MHz. Also included are muting, audio gain adjust (internal and external), low battery/carrier detect, and a wide range for the PLL reference frequency. The power supply range is 2.7 to 5.5 V. A data only (nonvoice) mode is also included.