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如何确定信号发生器54XX的绝对精度?



硬件: Signal Sources (AWG/FG/AO)>>Arbitrary Waveform and Function Generators>>PXI-5411

问题: 如何计算NI的信号发生器54xx的输出精度?

解答:

NI的函数信号发生器精度是依照行业标准以分贝显示的。为了得到板子的输出精度,需要将分贝表示转换成百分数误差,然后再乘以电压。下面以NI 5411为例:


当计算NI 5411的绝对精度时,需要考虑以下两方面因素

使用以下的计算公式我们能够得到输出的百分数误差:
                                                      Error (dB) = 20 log (1 + (Error (%)/100))
                                                      +/-0.1(dB) = 20 log (1 + (Error (%)/100))
                                                      Error (%) = 1.1579%

我们现在得到了电压的百分数误差,然后乘以输出信号的峰峰值电压(pk-pk voltage),同时加上“pre-attenuation offset”来得到输出信号的绝对精度:

                                              Accuracy (mV) = (voltage(mV) * Error (%)) + offset

例如:如果希望产生一个2V的信号,将会得到28.2mV左右的精度误差。



相关链接:

KnowledgeBase 42N6R6BF: Why is the Amplitude of the NI 54xx Output Signal Twice as Large as the Setting in the NI-FGEN?

 



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报告日期: 11/11/2002
最近更新: 08/24/2015
文档编号: 2RAHRIX4