Regardless of the application, an oscilloscope with deep memory offers numerous advantages that are difficult to live without. Thus, it is vital for users to understand the importance of a deep memory.
The sample rate of an oscilloscope only indicates the maximum sample rate that can be achieved. To determine the sample rate, users should know the memory depth of the oscilloscope. Given the oscilloscope’s memory depth and its typical time base settings, users can then calculate its sample rate.
Oscilloscopes stores samples into memory. The bigger the memory, the more samples can be stored, and the more samples are stored, the higher the sample rate. This implies that deeper memory allows users to sustain the oscilloscope’s maximum sample rate across a vast array of timebase settings. With the higher sustained sample rate, deeper memory also offers more reliable and accurate measurements.
One of the common challenge for oscilloscope users is how to effectively capture adequate cycles of both fast and slow signals simultaneously and maintain enough resolution to zoom in and view signal details. Insufficient resolution between points, leave users in the dark of what is really going on with their design while running the risk of completely missing events like glitches or anomalies. Without a fast deep memory oscilloscope, serious problems such as these can take hours or even days to finally discover.
Also, a shallower-memory oscilloscope compromises sample rate, providing an incomplete view of the digital and analog interaction in the design.
When signals behave badly during power up, even the most powerful triggering capability of the oscilloscope won’t solve the mystery of where to start looking for the cause. The only solution to the problem would be a deep memory, which provides users the ability to observe a full-start-up cycle with high resolution at longer periods of time. This effectively enables users to trace the path between the symptom as well as the root cause.
Deep memory also plays a critical role in analyzing the spectrum of signals. The frequency resolution is related directly to the amount of time displayed on the screen, with more time offering finer resolution. In addition, the maximum frequency that users can view is tied directly to sample rate — higher sample rate enables users to observe at a higher maximum frequency. Deep memory is required in capturing and viewing at longer periods of time and at higher resolution.
Overall, deep memory offers various things that users are looking for in an oscilloscope, such as the confidence that nothing is missed. An oscilloscope with deep memory delivers high resolution waveform capture attributed to its high sustained sample rate, the ability to trace symptoms back to its main cause when a good trigger event cannot be defined, and the ability to view at longer periods of time, which is especially useful when simultaneously viewing both digital and analog signals.
Rich Markley says
A good example of an application where a deep oscilloscope memory is important is analyzing slow signal events, such as switched-mode power supply transients or startup processes at board turn-on. Having a deep memory allows you to look at longer periods of time, which are important for these measurements. High resolution, and therefore deep memory, is also vital when trying to view fast and slow signals at the same time and correlate the behavior of the analog and digital signals in an embedded design.
Hope this helps,
Rich.,