SBAU315B July   2018  – March 2025 ADS9224R , ADS9234R

 

  1.   1
  2.   ADS9224REVM-PDK
  3.   Trademarks
  4. 1Overview
    1. 1.1 ADS9224REVM-PDK Features
    2. 1.2 ADS9224REVM Features
  5. 2Analog Interface
    1. 2.1 Connectors for Signal Source
    2. 2.2 ADC Differential Input Signal Driver
      1. 2.2.1 Input Signal Path
    3. 2.3 ADS9224R Internal Reference
  6. 3Digital Interfaces
    1. 3.1 multiSPI for ADC Digital IO
  7. 4Power Supplies
  8. 5Setup
    1. 5.1 Default Jumper Settings
    2. 5.2 EVM Graphical User Interface (GUI) Software Installation
  9. 6Operation
    1. 6.1 EVM GUI Global Settings for ADC Control
    2. 6.2 Register Map Configuration Tool
    3. 6.3 Time Domain Display Tool
    4. 6.4 Spectral Analysis Tool
    5. 6.5 Histogram Tool
  10. 7ADS9224REVM Bill of Materials, PCB Layout, and Schematics
    1. 7.1 Bill of Materials
    2. 7.2 PCB Layout
    3. 7.3 Schematics
  11. 8Revision History

2.3 ADS9224R Internal Reference

The ADS9224R device incorporates an internal 2.5-V band-gap reference and independently matched reference buffers for each ADC. The internal reference output pin (REFOUT) is decoupled with a 1-µF capacitor and can be probed at test point TP8. The internally matched reference buffers provide a gain of 1.6384 V/V. These reference buffers generate a high-precision, 4.096-V reference voltage for each ADC channel at pins REFP_A and REFP_B. These pins are decoupled with 10-µF decoupling capacitors. Additionally, a mid-reference output (REFby2) is available at test point TP5. This internal REFby2 buffer provides a common-mode voltage for input amplifiers driving the ADC inputs.