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

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.3 ADC Transfer Function

The ADS922x supports a ±3.2V differential input range. The device outputs 16-bit conversion data in either straight-binary or binary two's-complement formats. As shown in Table 7-1, the format for the output codes is the same across all analog channels. Configure the format for the output codes with the DATA_FORMAT field in register address 0x0D. The least significant bit (LSB) for the ADC is given by 1LSB = 6.4V / 216.

Table 7-1 Transfer Characteristics
INPUT VOLTAGE DESCRIPTION ADC OUTPUT IN 2's-COMPLEMENT FORMAT ADC OUTPUT IN STRAIGHT-BINARY FORMAT
≤ –3.2V + 1LSB Negative full-scale code 0x8000 0x0000
0V + 1LSB Mid-code 0x0000 0x7FFF
≥ 3.2V – 1LSB Positive full-scale code 0x7FFF 0xFFFF