SBASAG2C December   2023  – March 2025 ADS9227 , ADS9228 , ADS9229

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Thermal Information
    4. 6.4  Recommended Operating Conditions
    5. 6.5  Electrical Characteristics
    6. 6.6  Timing Requirements
    7. 6.7  Switching Characteristics
    8. 6.8  Timing Diagrams
    9. 6.9  Typical Characteristics: All Devices
    10. 6.10 Typical Characteristics: ADS9229
    11. 6.11 Typical Characteristics: ADS9228
    12. 6.12 Typical Characteristics: ADS9227
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Analog Inputs
      2. 7.3.2  Analog Input Bandwidth
      3. 7.3.3  ADC Transfer Function
      4. 7.3.4  Reference
        1. 7.3.4.1 Internal Reference Voltage
        2. 7.3.4.2 External Reference Voltage
      5. 7.3.5  Temperature Sensor
      6. 7.3.6  Data Averaging
      7. 7.3.7  Digital Down Converter
      8. 7.3.8  Data Interface
        1. 7.3.8.1 Data Frame Width
        2. 7.3.8.2 ADC Output Data Randomizer
        3. 7.3.8.3 Synchronizing Multiple ADCs
      9. 7.3.9  Test Patterns for Data Interface
        1. 7.3.9.1 Fixed Pattern
        2. 7.3.9.2 Digital Ramp
        3. 7.3.9.3 Alternating Test Pattern
      10. 7.3.10 ADC Sampling Clock Input
    4. 7.4 Device Functional Modes
      1. 7.4.1 Reset
      2. 7.4.2 Power-Down Options
      3. 7.4.3 Normal Operation
      4. 7.4.4 Initialization Sequence
    5. 7.5 Programming
      1. 7.5.1 Register Write
      2. 7.5.2 Register Read
      3. 7.5.3 Multiple Devices: Daisy-Chain Topology for SPI Configuration
        1. 7.5.3.1 Register Write With Daisy-Chain
        2. 7.5.3.2 Register Read With Daisy-Chain
  9. 8 Register Map
    1. 8.1 Register Bank 0
    2. 8.2 Register Bank 1
    3. 8.3 Register Bank 2
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Data Acquisition (DAQ) Circuit for ≤20kHz Input Signal Bandwidth
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Data Acquisition (DAQ) Circuit for ≤100kHz Input Signal Bandwidth
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Application Curves
      3. 9.2.3 Data Acquisition (DAQ) Circuit for ≤1MHz Input Signal Bandwidth
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

7.3.4.2 External Reference Voltage

Connect an external 4.096V reference voltage at the REFIO pin with an appropriate decoupling capacitor placed between the REFIO and REFM pins. For improved thermal drift performance, the REF7040 is recommended. To disable the internal reference, set PD_REF = 1b in address 0xC1 in register bank 1. The REFIO pin has electrostatic discharge (ESD) protection diodes connected to the AVDD_5V and REFM pins. Figure 7-3 shows an external reference diagram.

ADS9227 ADS9228 ADS9229 External Reference Voltage Figure 7-3 External Reference Voltage