Charting High-Resolution Oscilloscope Performance

Eric Bogatin, Signal Integrity Evangelist, Teledyne LeCroy

Figure 1. 8-bit vs. 12-bit oscilloscope waveforms.

There are hundreds of different oscilloscope models from a dozen different vendors. How do you make sense of all of their different features to pick the one instrument right for your application?  Here is a simple way of comparing high-resolution oscilloscopes.

High-resolution usually refers to the vertical resolution, the quantization of a waveform into a fixed number of vertical levels measured by the oscilloscope's Analog-to-Digital Converter (ADC). The more bits of vertical resolution, the more levels and the more detailed the waveform rendered. The earliest digital storage oscilloscopes (DSO) started as 8-bit resolution, or 256 vertical levels. But in the last ten years, as ADC chip technology got faster, higher resolution appeared in the industry, pioneered by Teledyne LeCroy.  Now, many oscilloscopes come with 10-bit and 12-bit vertical resolution. Why would you want higher resolution? The answer: the ability to see lower level signals and better dynamic range. An example of the difference between the same signal measured with an 8-bit and 12-bit oscilloscope is shown in Figure 1. 

Getting The Most Out Of Your Oscilloscope: Setup

Figure 1: Choosing a effective sample rate is key
to seeing the finer details of a waveform

Today's real-time digital oscilloscopes are so packed with bells and whistles (or "features," if you prefer) that you can forget how to use many of them. In fact, you might not even realize some exist! But they're all there for a reason, and they're all useful, maybe even more so than you know. To that end, we'll take a tour of a typical Teledyne LeCroy oscilloscope's features and give you some pointers as to how, and when, you can best take advantage of them.

The Periodic Table of Oscilloscope Tools: Capture

Figure 1: The Periodic Table of Oscilloscope Tools
is a handy reference to oscilloscopes' capabilities

Early analog oscilloscopes were quite a breakthrough in their day. For the first time, engineers and hobbyists were afforded the ability to "see" electrical signals displayed on a CRT as a function of voltage vs. time. The advent of analog oscilloscopes meant a new way to think about, compare, and visualize signals.