Texas Instruments AMC7812EVM-PDK, User Manual

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AMC7812EVM Software Overview
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The input range can be adjusted by clicking the button next to each ADC channel on the right-hand side of
the page. Conversions can be triggered by pressing the
Start Conv button or can be automatically
triggered before every read by enabling the Auto-Trigger check box. The ADC data registers, displayed on
the right side of the GUI, are updated with the converted results when the Read ADC button is pressed.
NOTE: The AMC7812EVM includes two OPA2320 devices, which are configured to buffer the
ADC2/ADC3 inputs. By default, the two inputs are connected to ground, this is accomplished
by using the J7 shunts. The default configuration for the shunts are located in
Table 4 . To
use the channels, remove the shunts and apply the desired voltage input to ADC2 or ADC3.
Most of the controls listed within the ADC image are used to setup the ADC configuration register. These
include the
conversion rate and conversion mode parameters, which are selectable through their
respective dropdown list. The selectable conversion rates are listed in Table 9 .
Table 9. Conversion Rates
Throughput (ADC0–ADC11)
Conversion Rate
(Single-Channel Auto Mode)
00 500 kSPS
01 250 kSPS
10 125 kSPS
11 62.5 kSPS
The conversion mode can be either Auto or Direct mode. In Direct Mode , the analog inputs, specified in
the ADC channel registers, are converted sequentially one time. In Auto Mode , the analog inputs are
converted sequentially and repeatedly. After a conversion is completed, the ADC multiplexer returns to the
first channel and repeats the process.
The ADCs also have an option to use an External or Internal reference. Select this option by using a
dropdown menu, then choosing the External or Internal option. When the Internal option is chosen, the
ADC External Ref Value box is grayed out. But when an External reference option is selected, the ADC
External Ref Value box becomes active and the value of external reference voltage can be entered in the
box as shown in Figure 16 .
Figure 16. ADC External Ref Value
The ADC Report window displays the decimal value for each activated ADC channel. If the Auto Read
button is pressed, the graph periodically updates with the new ADC value. To obtain new data, setup the
device for either Auto mode or Direct mode. If in Direct mode, verify that the
Trigger ADCs before read?
button is enabled. To stop the periodic updates press the Auto Read button once again. Figure 17 shows
the ADC Report window. Additionally, the Clear ADC Data button clears the memory of the chart.
16 AMC7812EVM-PDK User’s Guide SBAU177D – September 2010 – Revised August 2014
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