This DDS device is a numerically controlled oscillator employing a phase accumulator, a sine look-up table and a 10-bit D/A converter integrated on a single CMOS chip. Modulation capabilities are provided for phase modulation and frequency modulation.Clock rates up to 25 MHz are supported. Frequency accuracy can be controlled to one part in 4 billion. Modulation is effected by loading registers through the parallel microprocessor interface.A powerdown pin allows external control of a powerdown mode. The part is available in a 48-pin TQFP package.