SBAU411 February   2023 ADS127L21

 

  1.   Abstract
  2.   Trademarks
  3. 1EVM Overview
    1. 1.1 ADS127L21 EVM Kit
    2. 1.2 ADS127L21EVM Board
    3. 1.3 ADS127L21EVM-PDK-GUI Unsupported Features
    4. 1.4 Related Documentation
  4. 2Analog Interface
    1. 2.1 EVM Analog Input Options
    2. 2.2 ADC Connections and Decoupling
    3. 2.3 ADC Input Drive Amplifiers
    4. 2.4 VCOM Buffer
    5. 2.5 Onboard Voltage Reference
    6. 2.6 External Voltage Reference
    7. 2.7 Clock Tree
  5. 3Digital Interface
    1. 3.1 Serial Interface
    2. 3.2 I2C bus for Onboard EEPROM
  6. 4Power Supplies
    1. 4.1 Power Connection and Configuration
    2. 4.2 Low Dropout Regulator (LDO)
  7. 5ADS127L21 EVM Software Installation
  8. 6EVM Operation
    1. 6.1 Connecting the Hardware
    2. 6.2 Optional EVM Connections
    3. 6.3 EVM GUI Global Settings for ADC Control
    4. 6.4 Time Domain Display
    5. 6.5 Frequency Domain Display
    6. 6.6 Histogram Display
    7. 6.7 Digital Filter Configuration
    8. 6.8 Digital Filter Response
  9. 7Bill of Materials, Schematics, and Layout
    1. 7.1 Bill of Materials
    2. 7.2 Schematics
    3. 7.3 Board Layout

6.5 Frequency Domain Display

The spectral analysis tool, shown in #GUID-BFFCC5B6-1F96-42B4-8776-127E9A98E889, is intended to evaluate the dynamic performance (SNR, THD, SFDR, SINAD, and ENOB) of the ADS127L21 ADC through single-tone sinusoidal signal FFT analysis using the 7-term Blackman-Harris window setting. The FFT tool includes windowing options that are required to mitigate the effects of non-coherent sampling (this discussion is beyond the scope of this document). The 7-Term Blackman-Harris window is the default option and has sufficient dynamic range to resolve the frequency components of up to a 24-bit ADC. The None option corresponds to not using a window (or a rectangular window) and is not recommended.

GUID-20230125-SS0I-SKTM-SW9L-PF2CWJ7VZMNR-low.png Figure 6-6 Frequency Domain Display