高速数据采集模拟通道设计相关问题的研究

基于数据采集系统模拟通道的设计要求,针对高速模拟通道中元件的寄生参数、电源噪声和PCB板上的高频串扰等实际问题进行研究.采用阻容网络实现宽带信号的准确衰减,保证了通带内幅频特性的平坦度;采用宽带缓冲器件LH0033实现了阻抗变换,使用BNX005对电源进行EMI滤波,通过合理地线布局,减少高频信号在地线上的耦合,有效抑制了噪声,提高了模拟通道的抗干扰能力.实验结果表明采取上述措施后,50MHz的增益衰减由-2.5dB变为-0.26dB,电源噪声和信号噪声明显降低.

Research of analog channel in high-speed data acquisition system

Based on design requirements of analog channel of DAQ system, according to actual problems to be solved in high-speed analog channel, such as parasitic parameter of circuit element, source noise and high frequent crosstalk on PCB, research has been carried out. Uses resistor and capacitor network to achieve wide-band signal accurate reduction, ensuring the evenness terrain of amplitude frequency response characteristics in the pass band, and uses fast buffer amplifier LH0033 to achieve impedance transform This article uses BNX005 to filter the EMI from power network, and uses rational overall arrangement of ground, inhibiting noise effectively and enhancing ECCM capability of the whole analog channel. The experiment results show that gain attenuation in 50MHz has changed from -2.SdB to -0.26dB, and source noise and signal noise has reduced evidently, through above steps.