TiePie GMTO ATS5004D, Руководство пользователя

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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
Resolution
.
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).
Figure 3.10: The effect of the resolution
The ATS5004D measures at e.g. 12 bit resolution (2
12
=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
µ V.
3.5 Signal coupling
The ATS5004D has two different settings for the signal coupling:
AC and DC. In the setting DC, the signal is directly coupled to the
Introduction
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