Analog Devices EVAL-ADAS3022EDZ, Руководство пользователя

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UG-484 EVAL-ADAS3022EDZ User Guide
Rev. A | Page 14 of 32
Start Up
Refer to the numbered labels in Figure 18. Clicking the blue
buttons reveals the dialog boxes shown in Figure 19 through
Figure 27.
To begin evaluating the device, the on-board supplies must be
enabled.
•
RESET resets the ADAS3022 device to a known state.
Click RESET twice: once to reset the ADAS3022 and
again to bring it out of the reset state. Note that the
CFG is also reset to the default condition.
•
Reference Selection: At this time, it is recommended
to use the evaluation board’s externally generated
reference (default). To select the on-chip reference,
remove the P5 and P7 jumpers and click the button in
the
REF block to display the Reference Settings
dialog box, then choose REFERENCE ENABLED .
•
Auxiliary (AUX±) Channels Selection: The ADAS3022
allows the user to run it in default MUX ONLY mode
or by clicking on it to select the auxiliary channel
input pair (AUX+, AUX−)
IN0−INX AUX in normal
mode or sequencer mode. The IN0−INX AUX option
converts a dedicated channel through the internal
differential auxiliary channel pair (AUX+, AUX−)
with the specified input range of ±V
REF
. This option
bypasses the MUX and programmable gain instrumen-
tation amplifier stage, allowing direct access to the
SAR ADC core.
•
Update CFG : If the default configuration (channel, chan-
nel configuration, reference, and so on) is acceptable,
clicking
Update CFG writes to the ADAS3022 con-
figuration register (CFG). The ADAS3022 device is
configurable using a 16-bit on-chip register, CFG (refer
to the
ADAS3022 data sheet for more details). Note that
after changing any of the CFG register, this button
must be clicked
for the new setting to take effect.
Input Channel
To select the input channel, make a selection from the pull-
down menu (see Figure 20).
Channel Pairing
The channels can be paired (up to 4 maximum) or all channels
can be referenced to the COM input (see Figure 21).
Programmable Gain
The most useful and innovative feature of the ADAS3022 is the
on-chip programmable gain instrumentation amplifier. This
amplifier has the added flexibility of allowing for inputs ranging
from ±0.64 V to ±24.574 V. Select the appropriate setting for the
input voltage span, not including any common-mode signals,
since they are rejected. Note that the
ADAS3022 devices do not
need the usual level shifting that is common in SAR ADC
systems. The
ADAS3022 devices can accommodate fully
differential, single ended, and bipolar input signal types.
Software Controls
Within any of the chart panels, these controls are used to
control the display.
Controls the cursor.
Controls zooming in and out.
Controls panning.