SBVA094A February   2025  – July 2025 TPS7A21

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Oscilloscope Basics
  5. 2Implications of Parasitics
  6. 3Common Oscilloscope Issues
    1. 3.1 Choosing an Oscilloscope Probe
    2. 3.2 Sufficient Sampling
    3. 3.3 Visualization
    4. 3.4 Measuring Currents Using Current Probes
    5. 3.5 Bandwidth Limiting and Averaging
  7. 4Parasitic Effects on Common Measurements
    1. 4.1 Load Transients
    2. 4.2 Power Supply Rejection Ratio
    3. 4.3 Output Noise Voltage
  8. 5Summary
  9. 6References
  10. 7Revision History

Visualization

Oscilloscopes have the capability to zoom between several orders of magnitude, from 1s/div down to 500ps/div, or even smaller in high-performance oscilloscopes. This makes choosing an appropriate time scale important to effectively visualize the waveforms captured. When a waveform is not in visual focus, there can be difficulty distinguishing data at the rising and falling edges. When a waveform is illegible, the details of the electrical behavior can be lost. Taking a measurement with improper visualization can lead to concerns when debugging a measurement for future development. Figure 3-9 shows a load transient measurement which is displayed on a time scale that is too zoomed out for the measurement to be legible. Figure 3-10 shows a load transient measurement with a corrected timebase to account for distinguishing data on the rising edge. Figure 3-10 is an acceptable image for visualization.

 Poor VisualizationFigure 3-9 Poor Visualization
 Focus on the Rising
                        EdgeFigure 3-10 Focus on the Rising Edge