关于AD8428噪声问题 about noise of AD8428

     

搭建了AD8428电路测试,射频信号源从反向端输入一个300K正弦信号,正向输入端接地,输出噪声很大,用示波器测试输出,波形抖动严重;即使是输入全部接地,依然有很大的噪声输出,请问是电路问题吗还是AD8428本身噪声问题,如何解决

The AD8428 circuit test was built. The RF signal source input a 300K sinusoidal signal from the reverse end, and the forward input terminal is grounded. The output noise is very large. The output is tested by the oscilloscope, and the waveform jitter is serious. Even if the input is all grounded, there is still a big Noise output, is it a circuit problem or the noise problem of the AD8428 itself? How to solve it?



AD8428噪声about noise of AD8428
[edited by: bingtong at 1:03 AM (GMT 0) on 28 Aug 2019]
  • Hi Bingtong,

    Jitter is not a common specs for instrumentation amplifier. But I've seen a jitter test and they usually capture a lot of cycle of the input source as well as the output of the DUT and then get the difference or the variation to make sure that the jitter is caused by the DUT and not by the RF signal source itself.

    With regards to noise, the AD8428 has typical specs as shown on figure 29. Do you have measurement of AD8428 noise  when its input is grounded on the scope? What is the magnitude?

    Also, what is the magnitude of your input signal? Did you also intentionally lower the gain of the AD8428 by placing the R150?

    Best regards,

    Emman