Digitizing; Signal Coupling - TiePie Handyscope HS4 DIFF-5MHz Instrument Manual

3.4

Digitizing

When digitizing the samples, the voltage at each sample time is
converted to a number. This is done by comparing the voltage
with a number of levels. The resulting number is the number cor-
responding to the level that is closest to the voltage. The number
of levels is determined by the resolution, according to the following
relation: LevelCount = 2
The higher the resolution, the more levels are available and the
more accurate the input signal can be reconstructed. In figure 3.10,
the same signal is digitized, using two different amounts of levels:
16 (4-bit) and 64 (6-bit).
The Handyscope HS4 DIFF measures at e.g. 12 bit resolution
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(2 =4096 levels). The smallest detectable voltage step depends
on the input range. This voltage can be calculated as:
V oltageStep = F ullInputRange/LevelCount
For example, the 200 mV range ranges from -200 mV to +200
mV, therefore the full range is 400 mV. This results in a smallest
detectable voltage step of 0.400V/4096 = 97.65 µV.
3.5

Signal coupling

The Handyscope HS4 DIFF has two different settings for the signal
coupling: AC and DC. In the setting DC, the signal is directly
Figure 3.10: The effect of the resolution
.
Introduction
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