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    sboa066

    How to measure an opamp's noise charaeterization?
    [size=2]Best Regards,[/size]
    [size=2]Hughes[/size]

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    how to measure noise spectral density

    The idea is simple. In general You need a true RMS voltmeter and bandpass filter. Connect the OP in circuit that hi will be used, connect to the input ( in place of signal source) resistor ith the same impedance. Bandpass filter must be connected to the output of the OP circuit and after that connect the true RMS voltmeter. In real the OP noise is small, and that s why you will need additional amplifier, or very sensetive true RMS voltmeter. For example if you measure 20uV in frequency band 100-100KHz that is mean that that amplifier have noise spectral density arround 63nV/sqrt(Hz), beacause 20*exp-6/sqrt(100 000 - 100).



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    how to measure an opamp

    I think, in addition, BPF must be variable band...as its hard to take measured output for certain frequency limits.
    With my Respect,



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    how to measure noise at the opamp output

    Noise Analysis for High Speed Op Amps

    http://www-s.ti.com/sc/psheets/sboa066/sboa066.pdf



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    Re: How to measure an opamp's noise charaeterization?

    Thanks all. So the measured results are the total noise power, not the noise power spectrum density, right? And how to measure the spectrum density?
    [size=2]Best Regards,[/size]
    [size=2]Hughes[/size]



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