SBAU433B November   2025  – April 2026

 

  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 Specifications
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 Analog Inputs
      1. 2.1.1 Differential Current Input Channels
      2. 2.1.2 Differential Voltage Inputs Channels
      3. 2.1.3 Combined Differential Current and Voltage Input Channels
      4. 2.1.4 Single-Ended Current Input Channels
    2. 2.2 ADC Connections and Decoupling
    3. 2.3 Digital Interface
    4. 2.4 Power Supplies
    5. 2.5 Voltage Reference
    6. 2.6 Clocking
    7. 2.7 Using the ADS125H18 EVM With an External Controller
  9. 3Software
    1. 3.1 Software Description
    2. 3.2 ADS125H18 GUI Installation
  10. 4Implementation Results
    1. 4.1 Hardware Connections
    2. 4.2 GUI Operation
      1. 4.2.1 ADC Capture Settings and Sequencer Configuration
      2. 4.2.2 Time-Domain Display
      3. 4.2.3 Frequency-Domain Display
      4. 4.2.4 Histogram Display
      5. 4.2.5 EVM Register Settings
  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. 7Revision History

2.5 Voltage Reference

Figure 2-8 shows an optional external voltage reference circuit included on the ADS125H18 EVM. The ADS125H18 integrates a low-noise, low-drift voltage reference that is sufficient for most applications. Alternatively, the EVM supports two external voltage reference options if desired. First, install header pin J11 and apply an external voltage source to this pin. Second, the EVM includes the 2.5V voltage reference REF6025 and the surrounding circuitry. However, these components are not included on the EVM by default and therefore must be installed by the user. Verify that any external reference voltage applied to the ADC meets the voltage requirements as described in Table 1-1. Additionally, configure the ADC registers as needed to use an external reference. Refer to the ADC datasheet for more information.

ADS125H18EVM-PDK Optional External Reference Voltage Circuit Figure 2-8 Optional External Reference Voltage Circuit