原标题：ADI AD9914 3.5 GSPS直接数字合成器(DDS)解决方案

　　ADI公司的AD9914是集成了12位DAC 3.5 GSPS直接数字合成器(DDS),采用先进的DDS技术,和高速高性 DAC一起组成数字可编程完整的高频合成器,能产生高达1.4GHz的模拟输出正弦波,调频分辨率190 pHz,16位调相分辨率,可编程模数,自动线性和非线性扫频功能,32位并行数据通路接口,相位噪音−128 dBc/Hz ,宽带SFDR小于-50dBc,主要用于LO频率合成,可编程时钟发生器,用于雷达和扫描系统的FM调频脉冲,测试和测量设备,极性调制器,快速跳频和声光器件驱动器等.本文介绍了AD9914主要特性,框图和功能框图,以及AD9914评估板电路图和材料清单(BOM).

　　The AD9914 is a direct digital synthesizer (DDS) featuring a 12-bit DAC. The AD9914 uses advanced DDS technology, coupled with an internal high speed, high performance DAC to form a digitally programmable, complete high frequency synthesizer capable of generating a frequency-agile analog output sinusoidal waveform at up to 1.4 GHz. The AD9914 enables fast frequency hopping and fine tuning resolution (64-bit capable using programmable modulus mode). The AD9914 also offers fast phase and amplitude hopping capability. The frequency tuning and control words are loaded into the AD9914 via a serial or parallel I/O port. The AD9914 also supports a user defined linear sweep mode of operation for generating linear swept waveforms of frequency, phase, or amplitude. A high speed, 32-bit parallel data input port is included, enabling high data rates for polar modulation schemes and fast reprogramming of the phase, frequency, and amplitude tuning words.

　　The AD9914 is specified to operate over the extended industrial temperature range.

　　AD9914主要特性:

　　3.5 GSPS internal clock speed

　　Integrated 12-bit DAC

　　Frequency tuning resolution to 190 pHz

　　16-bit phase tuning resolution

　　12-bit amplitude scaling

　　Programmable modulus

　　Automatic linear and nonlinear frequency sweeping capability

　　32-bit parallel datapath interface

　　8 frequency/phase offset profiles

　　Phase noise: −128 dBc/Hz (1 kHz offset at 1396 MHz)

　　Wideband SFDR < −50 dBc

　　Serial or parallel I/O control

　　1.8 V/3.3 V power supplies

　　Software and hardware controlled power-down

　　88-lead LFCSP package

　　PLL REF CLK multiplier

　　Phase modulation capability

　　Amplitude modulation capability

　　AD9914应用:

　　Agile LO frequency synthesis

　　Programmable clock generator

　　FM chirp source for radar and scanning systems

　　Test and measurement equipment

　　Acousto-optic device drivers

　　Polar modulator

　　Fast frequency hopping

　　图1.AD9914方框图

　　图2.AD9914功能框图

　　AD9914评估板

　　This user guide describes how to set up and use the AD9914evaluation board. The AD9914 is a 3.5 GSPS DDS with a 12-bit DAC.

　　The evaluation board software provides a graphical user interface (GUI) for easy communication with the device along with many user-friendly features such as the mouse-over effect.

　　This user guide is intended for use in conjunction with the AD9914 data sheet.

　　图3.AD9914评估板外形图