动态范围与纹波测量.pdf

力科创新火炬传递之第4棒 关键词： Vertical Scaling and Signal Integrity Make Maximizing Signal Integrity Make Maximizing Signal Integrity Across Multiple Channels! Across Multiple Channels! The peak-to-peak (pkpk) parameter measurement shows a value of 6.41 V for this waveform. The waveform is occupying (6.41V)/(8V) = 80.1% of full scale. LeCroy Company Confidential The noise riding on the top of the pulse can be isolated and monitored, by adjusting the measurement gates to measure pkpk on the top of the pulse only. LeCroy Company Confidential To ensure statistical accuracy, 1000 acquisitions are taken, and the pkpk of the top of the pulse is measured each time. With vertical scaling of 1 V/div, the mean value of noise on the pulse is 886.7 mV. LeCroy Company Confidential Changing vertical scaling to 5 V/div, the mean value of pkpk noise has now changed to 1.783 V. LeCroy Company Confidential Vertical Scale and Amplitude Error Further adjusting vertical scaling shows that channel vertical scaling significantly affects the measured noise level. At 550 mV/div, the mean noise level is 821 mV; at 2 V/div, the noise level is 1.02 V, and at 10 V/div, the noise level is 3.06V. Between 2 V/div and 10 V/div, the measured noise level tripled (factor of 3x) when changing the V/div by a factor of 5x. LeCroy Company Confidential Dynamic range also affects timing measurements. Note below the standard deviation of risetime, falltime, pulse width, and period measurements. LeCroy Company Confidential Note how changing V/div settings has affected standard deviation of timing measurements. LeCroy Company Confidential Vertical Scale and Timing Measurement Summary: Adjusting the vertical scaling of waveforms also affects the accuracy of timing me