Evaluating Performance with the ADCPro Software
The Data Rate control on the main plug-in window sets the data rate for the ADS8638. Changing the data
rate controls the time between sequential conversions once the acquisition period begins.
In the Basic Settings window, the Operating Mode and Input Range options are available. The plug-in was
designed to only use auto-mode channel sequencing, and therefore manual mode is not selectable. The
input range option allows the user to select the desired analog input voltage range from +5 V, +10 V,
±
2.5 V,
±
5 V, or
±
10 V. This setting becomes the range for all the channels that are enabled at the time of
data acquisition.
The Power Blocks window includes buttons to enable the internal reference voltage and the internal
temperature sensor. By default, these two options are disabled and are enabled once the appropriate
button is selected.
The About this plug-in tab has the plug-in version history along with the firmware version. The Notes
indicator shows manufacturing information about the EVM that is stored in the EVM EEPROM, and may
show relevant notes about the plug-in or firmware code, if any.
At the bottom of the Device Config window is the PowerDown button. Use this button to direct the
processor to write the command that puts the ADC into power-down mode.
7.1.2
Channels 1-4 Tab and 5-8 Tab
These two tabs, as shown in
, are used to enable/disable the ADC channels as well as configure
the alarm states. By default, all of the eight channels are disabled. Before an acquisition can be
performed, at least one channel must be enabled. Once a channel is enabled, the alarm high and alarm
low thresholds can be set along with the respective hysteresis limits. As the converted result exceeds the
alarm threshold, the LED found on the EVM board should turn on to indicate an alarm.
As multiple channels are enabled, the effective data rate decreases. The ADS8638 uses an architecture
that relies on an internal cycling mux, requiring the conversions to be completed in a sequential order
rather than simultaneously. The data rate displayed in the top right corner of the plugin refers to all
enabled channels to be converted.
16
ADS8638EVM-PDK
SBAU192
–
July 2011
Copyright
©
2011, Texas Instruments Incorporated
