SBAU427 July   2025 ADS131E08

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Device Information
    4. 1.4 Specification
  8. 2Hardware
    1. 2.1 EVM Analog Inputs
    2. 2.2 Power Supplies
    3. 2.3 ADC Connections and Decoupling
    4. 2.4 Voltage Reference
    5. 2.5 Op Amp Common-Mode Bias
    6. 2.6 Digital Interface
    7. 2.7 EEPROM
  9. 3Software
    1. 3.1 Software Description
    2. 3.2 Software Installation
  10. 4Implementation Results
    1. 4.1 Hardware Connections
    2. 4.2 Optional EVM Configuration
    3. 4.3 GUI Software Operation
      1. 4.3.1 EVM Register Settings
      2. 4.3.2 GUI Settings for ADC Control
      3. 4.3.3 Time Domain Display
      4. 4.3.4 Frequency Domain Display
      5. 4.3.5 Histogram Display
  11. 5Hardware Design Files
    1. 5.1 Schematics
    2. 5.2 PCB Layouts
    3. 5.3 Bill of Materials (BOM)
  12. 6Additional Information
    1. 6.1 Trademarks

2.2 Power Supplies

The ADS131E08 EVM is directly powered by the PHI controller by default. The PHI provides 5.5V to a TPS7A47 LDO. The LDO output provides a stable supply for the ADC analog supply (AVDD). The default output of the LDO is 5V and can be reprogrammed to output 3V by populating or depopulating R42, R43, and R45. The PHI also supplies the voltage for the ADC digital supply (DVDD). Figure 2-2 shows the power supply circuitry. The EVM optionally supports external power supplies. Provide external power supplies by following the steps outlined below:

  1. Depopulate R25 and populate R40 to use an external supply for DVDD. Provide the DVDD supply voltage through terminal block J14.
  2. Move JP2 jumper to connect +VinExt to +LDO_Vin to provide an external supply to the LDO. Provide external power to the LDO though terminal block J14.
  3. Remove R44, install TP10 and apply the AVDD voltage to TP10 to power AVDD directly without using the onboard LDO.

The ADS131E08EVM only supports unipolar power supplies.

The AVDD voltage rail also includes an indicator LED to verify the LDO is working properly. AVDD and DVDD have a test point for convenient verification of power supply functionality.

ADS131E08EVM-PDK Power Supply CircuitryFigure 2-2 Power Supply Circuitry