What Is an Oscilloscope and How Does it Work?
An oscilloscope is a device that samples a signal as it changes over time and then plots that signal on a display. The amplitude of the signal is plotted on the vertical axis of the display, and time is displayed on the horizontal axis. “A picture is worth a thousand words!” Modern digital oscilloscopes can display signal changes that occur over time as long as hours or as short as billionths of a second. Because oscilloscopes must be able to digitize signals that can vary by the nanosecond, the analog-to-digital converter in an oscilloscope must work very differently than those in multimeters. To make very fast measurements, many oscilloscopes use the technique of measuring input signals with multiple, parallel comparators. To make a measurement, the signal is applied to all of the comparators at once, and each comparator compares the signal level to a unique reference voltage. If the signal equals or exceeds the comparator’s reference voltage, the comparator changes its digital bit f
