Agilent Technologies 54621D, 24A, 42A, 22A All points displayed after Single or Stop, Peak Detect

MegaZoom Concepts and Oscilloscope Operation

Acquisition Modes

Normal Mode

For the majority of use models and signals, Normal acquisition mode yields the best oscilloscope picture of the waveform.

The analog channels can have up to 2 million samples per channel for the 54620-series and up to 4 million samples per channel for the 54640-series behind the 1,000-pixel column oscilloscope display. Some compression of samples to display points is obviously necessary, but due to the high plot rate (up to 25 million vectors/second), the compression is much less that previous oscilloscopes. This means the signal will look “right” at many more operating points.

All points displayed after Single or Stop

After a Single acquisition or when the oscilloscope has been stopped, all acquired points are displayed.

Peak Detect

Peak Detect is useful if you are interested in capturing a narrow event relative to the time window of interest. Using Peak Detect and infinite persistence together is a powerful way to find spurious signals and glitches.

54620-seriesPeak detect acquire mode displays any signal pulse wider than 5 ns, allowing you to find glitches and narrow spikes regardless of sweep speed. Because of MegaZoom memory, peak detect is only necessary at sweep speeds of 1 ms/div and slower. At faster sweep speeds, Normal acquire mode can capture the narrow peaks.

At sweep speeds slower than 1 ms/div, the oscilloscope can acquire more samples than can fit into MegaZoom memory. The oscilloscope selects samples to store such that no local minimum or maximum wider than 5 ns is missed. In peak detect mode, narrow glitches and sharp edges are displayed more brightly than when in Normal acquire mode, making them easier to see.

54640-seriesPeak detect acquire mode displays any signal pulse wider than 1 ns, allowing you to find glitches and narrow spikes regardless of sweep speed. Because of MegaZoom memory, peak detect is only necessary at sweep speeds of 500 ∝ s/div and slower. At faster sweep speeds, Normal acquire mode can capture the narrow peaks.

At sweep speeds slower than 500 ∝ s/div, the oscilloscope can acquire more samples than can fit into MegaZoom memory. The oscilloscope selects samples to store such that no local minimum or maximum wider than 1 ns is missed. In peak detect mode, narrow glitches and sharp edges are displayed more brightly than when in Normal acquire mode, making them easier to see.

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