Texas Instruments ADS7042EVM-PDK, User Manual

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4.5 Histogram Analysis
Noise degrades ADC resolution and the Histogram Analysis tool can be used to visualize the ADC noise
performance. Noise couples to the ADC output from sources such as the input drive circuits, the ADC power
supply, and the ADC itself. The cumulative effect of this noise is reflected in the standard deviation of the ADC
output code histogram obtained by performing multiple conversions of a DC input. As shown in
Figure 4-5 , click
the Capture button to display a histogram corresponding to a DC input.
Figure 4-5. Histogram Analysis in the ADS704X-5XEVM GUI
4.6 Updating EEPROM After ADC Replacement
As discussed in Section 1 , the ADS704X-5XEVM can support operation of the 14 different ADCs shown in Table
1-2 . See Section 2.1.1 for information about the required hardware modifications for replacing a single-ended
input ADC and Section 2.1.2 for information about the required hardware modifications for replacing a differential
input ADC.
When the hardware modifications are complete, update the EEPROM so the GUI reflects the newly installed
devices on the EVM. Follow these steps to update the EEPROM from the ADS704X-5XEVM GUI:
1. Set switch S1 to write enable by pushing the switch closest to the WR_EN silkscreen text (see Figure 2-1 )
2. Navigate to Tools → Load EEPROM in the menu at the top left of the GUI
3. In the pop-up window illustrated in Figure 4-6 , select the appropriate device for both ADC A (U3 or U8) and
ADC B (U5 or U9)
a. ADC A corresponds to the single-ended input path and ADC B corresponds to the differential input path
4. Click the Load EEPROM button in the pop-up window
5. Verify the EEPROM loaded correctly by reviewing the ADC name in the upper left corner of the GUI, the
supported devices in the upper right of the GUI, and the Active Device drop-down menu (see Figure 4-7 )
a. In this example, ADC A was changed from ADS7049-Q1 to ADS7040 and ADC B was changed from
ADS7047 to ADS7044
6. Set switch S1 to write disable by pushing the switch closest to the WR_DIS silkscreen text (see Figure 2-1 )
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SBAU382 – NOVEMBER 2021
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ADS7042EVM-PDK, ADS7049-Q1EVM-PDK, and ADS7057EVM-PDK
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