Evaluating Oscilloscope Vertical Noise Characteristics
White Papers
All oscilloscopes exhibit one undesirable characteristic: Vertical noise in the scope’s analog frontend and digitizing process. Measurement system noise will degrade your actual signal measurement accuracy, especially when you are measuring low-level signals and noise. Since oscilloscopes are broadband measurement instruments, the higher the bandwidth of the scope, the higher the vertical noise will be – in most situations. Although engineers often overlook vertical noise characteristics when they evaluate oscilloscopes for purchase, these characteristics should be carefully evaluated as they can impact signal integrity measurements in several ways. Vertical noise:
- Induces amplitude measurement errors
- Induces sin(x)/x waveform reconstruction uncertainty
- Induces timing errors (jitter) as a function of input signal edge slew rates
- Produces visually undesirable “fat” waveforms