AD9831

a DIRECT DIGITAL SYNTHESIZER, WAVEFORM GENERATOR FEATURES 3 V/5 V Power Supply 25 MHz Speed On-Chip SINE Look-Up Table On-Chip 10-Bit DAC Parallel Loading Powerdown Option 72 dB SFDR 125 mW (5 V) Power Consumption 40 mW (3 V) Power Consumption 48-Pin LQFP APPLICATIONS DDS Tuning Digital Demodulation MCLK FSELECT FREQ0 REG FREQ1 REG AD9831 GENERAL DESCRIPTION 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 LQFP package. Similar DDS products can be found at http://www.analog.com/DDS. FUNCTIONAL BLOCK DIAGRAM DVDD DGND AVDD AGND REFOUT FS ADJUST REFIN ON-BOARD REFERENCE FULL-SCALE CONTROL COMP MUX PHASE ACCUMULATOR (32-BIT) 12 Σ SIN ROM 10-BIT DAC IOUT PHASE0 REG PHASE1 REG PHASE2 REG PHASE3 REG MUX PARALLEL REGISTER TRANSFER CONTROL MPU INTERFACE AD9831 SLEEP RESET D0 D15 WR A0 A1 A2 PSEL0 PSEL1 REV. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infr...