基于AD9850和MAX7490用于仪器校准信号源电路的设计  

Design of calibration signal source circuit based on AD9850 and MAX7490

作　　者：王亚磊 周静雷[1] WANG Yalei;ZHOU Jinglei(Electronic Information institute,Xi＇ an Polytechnic University,Xi＇ an 710048,China)

机构地区：[1]西安工程大学电子信息学院,陕西西安710048

出　　处：《电声技术》2018年第5期52-56,共5页Audio Engineering

基　　金：陕西省教育厅专项科研项目(11JK0548)资助

摘　　要：功率试验是扬声器生产过程中必经的一个测试环节,功率试验测试信号的种类有多种,为了提高功率试验系统在功率试验时的精度,设计一款基于AD9850和MAX7490用于仪器校准的信号源电路。该设计由直接数字合成器AD9850产生幅值为500mV,频率为1kHz的标准正弦信号,然后使用该信号对功率实验仪硬件电路中衰减和放大网络的实际衰减和放大倍数进行计算标定。由于该芯片内的DAC输出的信号中含有高频谐波,所以需要将该信号经过椭圆低通滤波器和基于MAX7490设计的四阶带通滤波器处理。经过对实际测量数据和波形的分析,电路实际参数标定准确,滤波电路滤波效果良好。Power test is a necessary test link in the production of loudspeaker. There are many kinds of power test and test signals. In order to improve the precision of power test system in power test, a signal source circuit based on AD9850 and MAX7490 for instrument calibration is designed. This design uses a direct digital synthesizer AD9850 to produce a standard sinusoidal signal with a amplitude of 500 mV and a frequency of 1 kHz. The signal is used to calibrate the actual attenuation and magnification of the attenuation and amplification networks in the hardware circuit of the power experiment instrument. Because of the high frequency harmonic in the DAC output signal in the chip, it is necessary to process the signal through the elliptical low pass filter and the four order bandpass filter based on the MAX7490 design. After analyzing the measured data and waveform, the actual parameters of the circuit are calibrated accurately, and the filtering effect of the filter circuit is good.

关 键 词：MAX7490 AD9850 信号源 带通滤波器 标定 

分 类 号：TN409[电子电信—微电子学与固体电子学]