Abstract
It briefly introduced the function, internal structure, pin array and typical apply circuit of The AD7008 direct digital synthesis chip. The AD7008 direct digital synthesis chip is a numerically controlled oscillator employing a 32-bit phase accumulator, sine and cosine look-up tables and a 10-bit D/A converter integrated on a single CMOS chip. It also provided for phase modulation, frequency modulation, and both in-phase and quadrature amplitude modulation suitable for QAM and SSB. It is a Super-heterodyne receiver .It’s Clock rates up to 20MHz and 50MHz are supported, the frequency accuracy of it is very high. Modulation may be effected by loading registers through the parallel microprocessor interface or the serial interface. A power-down pin allows external control of a power-down mode. The AD7008 is available in 44-pin PLCC. It widely used in Frequency Synthesizers、Frequency, Phase or Amplitude Modulators、DDS Tuning and Digital Modulation.
Key words: Numerically Controlled Oscillator CMOS
Super-heterodyne receiver DSP processor Microprocessor
