The RF2513 is a monolithic integrated circuit intended for use as a low-cost frequency synthesizer and transmitter. The device is provided in a 24 pin SSOP package and is designed to provide a phased locked frequency source for use in local oscillator or transmitter applications. The chip can be used in FM or FSK applications in the U.S. 915MHz ISM band and European 433MHz or 868MHz ISM band. The integrated VCO, dual-modulus/dual-divide (128/129 or 64/65) prescaler, and reference oscillator require only the addition of an external crystal to provide a complete phase-locked oscillator. A second reference oscillator is available to support two channel applications.