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<< Contents
<< Workbar
<< WorkBar Tabs
<< Channels Tab
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The threshold level determines how the logic analyzer interprets the input signals.
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Input voltages "below" the threshold are converted to '0' (logic-low).
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Input voltages "above" the threshold are converted to '1' (logic-high).
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In the example below, the green sample-points are above the threshold level and are interpreted as a logic-high. The yellow sample-points are below the threshold level and are interpreted as a logic-low.
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A small indeterminate voltage range exists around the threshold voltage level...
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The input signal value is unpredictable in this small region near the threshold voltage. This region is defined by the precision limits of the logic analyzer's voltage sensors.
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Always define the threshold levels so the input signals spend the least possible time in this indeterminate voltage range.
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For example, avoid setting the threshold to 0.1 V if the signals logic-low voltage is 0 V. Set the threshold well above this 0 V logic-low "noise floor".
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The Appendices define each model's minimum voltage swing.
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Click the threshold buttons in the Channels view to set the threshold levels...
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Logic Family
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Select a logic family to set the threshold level to a "typical" threshold voltage for that logic type. This default threshold level is normally mid-way between the logic-low and logic-high voltages.
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The logic family does not limit the logic analyzer's threshold boundaries.
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Regardless of the selected logic family, the threshold level can be adjusted to any voltage the logic analyzer supports.
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The Appendices define each model's threshold voltage limits.
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Edit Box
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Enter a threshold level voltage.
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Up / Down Buttons
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Make minimum step-adjustments to the threshold voltage level.
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Scroll Bar
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Make quick threshold level changes with the scroll bar slider.
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The selected logic family affects the appearance of the scroll bar.
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The green center region suggests the best threshold range for the logic family.
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The regions on either side of the green area are outside the typical threshold voltage for the active logic family.
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However, the active logic family does not affect the scale of the scroll bar. The threshold level can be adjusted to any voltage the logic analyzer supports.
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The scroll bar's end tick-marks display the minimum (left) and maximum (right) threshold voltage limits.
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The Appendices define each model's threshold voltage limits.
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Copyright and trademark information
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