SBAU435 February   2024 ADS127L18

 

  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 Specification
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1  EVM Analog Input Options
    2. 2.2  Power Requirements
    3. 2.3  ADC Connections and Decoupling
    4. 2.4  ADC Input Amplifiers
    5. 2.5  VCOM Buffer
    6. 2.6  Voltage Reference
    7. 2.7  Reference Buffer
    8. 2.8  Clock Tree
    9. 2.9  Serial Interface
    10. 2.10 EEPROM
    11. 2.11 Power Supplies
    12. 2.12 Low Dropout Regulator (LDO)
  9. 3Software
    1. 3.1 Software Description
    2. 3.2 ADS127L18 EVM Software Installation
  10. 4Implementation Results
    1. 4.1 EVM Operation
      1. 4.1.1 Evaluation Setup
      2. 4.1.2 Optional EVM Connections
      3. 4.1.3 EVM Register Settings
      4. 4.1.4 ADC Capture Settings
        1. 4.1.4.1 ADC Configuration
        2. 4.1.4.2 Clocking Configuration
        3. 4.1.4.3 SPI and Data Port Configuration
        4. 4.1.4.4 Filter Configuration
        5. 4.1.4.5 Channel Configuration
      5. 4.1.5 Time Domain Display
      6. 4.1.6 Spectral Analysis Display
      7. 4.1.7 Histogram Analysis 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
  13. 7Related Documentation
    1. 7.1 Supplemental Content

2.7 Reference Buffer

Figure 3-7 shows the onboard reference buffer. The OPA211 amplifier U9 was selected for low voltage offset, low offset drift, and low noise. The amplifier topology is designed to drive capacitive loads. For information on this topology, see the Op Amp Stability Videos in TI Precision Labs. The default connection for the reference buffer input is the REF7040 reference output through resistor R76. To connect the reference buffer output to the ADS127L18 input, populate resistor R75 and remove resistors R62 and R63.

GUID-20240108-SS0I-DXD2-JPL3-D4HL61FK227N-low.svg Figure 2-7 Reference Buffer