SBAU413A october   2022  – may 2023

 

  1.   Abstract
  2.   Trademarks
  3. 1EVM Overview
    1. 1.1 ADS131B26Q1EVM-PDK Features
    2. 1.2 ADS131B26Q1EVM-PDK Quick-Start Guide
  4. 2Analog Interface
    1. 2.1 Terminal Blocks and Test Points
    2. 2.2 ADC1A and ADC1B
    3. 2.3 ADC2A and ADC2B
    4. 2.4 ADC3A and ADC3B
  5. 3Digital Interface
    1. 3.1 Connection to the PHI Controller
    2. 3.2 Digital Header
    3. 3.3 Clock Options
  6. 4Power Supplies
    1. 4.1 DC/DC Converter Circuit
    2. 4.2 ADC Power Supplies
    3. 4.3 Power Supply and Voltage Reference Decoupling
  7. 5ADS131B26Q1EVM-PDK Initial Setup
    1. 5.1 Default Jumper Settings
    2. 5.2 EVM Graphical User Interface (GUI) Software Installation
  8. 6ADS131B26Q1EVM-PDK Software Reference
    1. 6.1 Global Settings for ADC Control
    2. 6.2 Register Map Configuration
      1. 6.2.1 Register Map Basics
      2. 6.2.2 ADC1A, ADC3A and ADC1B, ADC3B Configuration
      3. 6.2.3 ADC2A and ADC2B Configuration
    3. 6.3 Analysis Tools
      1. 6.3.1 Time Domain Display
      2. 6.3.2 Spectral Analysis Tool
      3. 6.3.3 Histogram Analysis
      4. 6.3.4 Sequencer Analysis
  9. 7ADS131B26Q1EVM-PDK Bill of Materials, PCB Layout, and Schematics
    1. 7.1 Bill of Materials (BOM)
    2. 7.2 PCB Layout
    3. 7.3 Schematics
  10. 8Revision History

4.3 Power Supply and Voltage Reference Decoupling

The power supply and ADC voltage reference pins for the ADS131B26-Q1 are bypassed with ceramic capacitors placed close to the supply pins. Additionally, the EVM layout uses thick traces or large copper fill areas, where possible, between bypass capacitors and loads to minimize inductance along the load current path.

The EVM schematic lists the analog and digital grounds (AGND and DGND) as separate net names for the purpose of circuit illustration. However, these two nets are connected on the EVM by a net-tie on the bottom signal layer. Proper component placement and solid ground pours are important to make sure that the lowest noise and highest accuracy is used in any precision ADC application. See Section 7.2 for more suggested layout practices.