How to Use Memory Properly

In a recent post, we addressed setting sample rate for serial data acquisition, but let’s look again at how time per division (time/div), memory length and sample rate all interact, and what you can do to optimize your use of oscilloscope capture memory when setting up your timebase.

Figure 1: Sample rate as a function of time/div for three different memory lengths.
Longer memory extends the range of time/div settings that support the highest sample rate.

How Many Channels is Enough?

Figure 1: A switch-mode power supply driving a fixed load

can be designed and optimized specifically for that load.

The bulk of oscilloscope applications are well served by instruments with four analog input channels. Most basic debugging and design-related work involves probing of only one signal at a given time, and occasionally more than one, especially when differential signals are concerned. Thus, many users may never see a need for an oscilloscope with more than four channels.

Having said that, there are some applications that by their very nature surpass four channels. Moreover, some of these applications concern circuits and devices that are produced in extremely high volumes. A case in point is switch-mode power supplies, such as those typically found in notebook PCs, tablets, or embedded systems.