PDK Kit Operation
7.3
Using the ADS8861EVM Plug-in
The ADS8861EVM allows the user to evaluate the ADS8861 ADC.
shows the device
configuration tab of the ADS8861EVM plug-in that is used to change acquisition parameters such as
sample rate and voltage reference.
Figure 10. ADS8861EVM Plug-In: Device Configuration Tab
The device configuration tab contains the following controls:
•
Data rate:
By default, data rate is 1 MSPS. This control shows the data rate or sampling frequency
used by the ADC to acquire data. With an SCLK frequency of 80 MHz, data rate can be set from
19.536 kSPS to 1 MSPS. With an SCLK frequency of 10 MHz, data rate can be set from 4 kSPS to
344.827 kSPS.
•
SCLK:
By default, SCLK is 80 MHz. SCLK sets the clock frequency used by the SPI interface to
capture data. SCLK should be between 70 MHz to 80 MHz for 1 MSPS. For slow sampling rates, use
10 MHz. Do not use SCLK frequencies between 30 MHz and 50 MHz.
•
Reference:
4.5 V is the default reference value, which matches the onboard reference of the EVM.
The value of this control should always match the reference used by the ADC to read accurate
voltages.
•
Device selection:
The ADS8861 is selected by default.
•
About:
This control shows the motherboard name, plug-in version, firmware version, assembly date,
and board revision information. Note that the device name displayed is ADS8881 instead of ADS8861
because the main software is based on the ADS8881 device.
•
Collection bar:
This feature shows the percentage of data collected during an acquisition session.
13
SBAU214 – October 2013
ADS8861EVM-PDK
Copyright © 2013, Texas Instruments Incorporated