SBASA81B January   2023  – October 2024 ADS9815 , ADS9817

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 Timing Diagrams
    9. 5.9 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Analog Inputs
        1. 6.3.1.1 Input Clamp Protection Circuit
        2. 6.3.1.2 Programmable Gain Amplifier (PGA)
        3. 6.3.1.3 Wide-Common-Mode Voltage Rejection Circuit
        4. 6.3.1.4 Gain Error Calibration
      2. 6.3.2 ADC Transfer Function
      3. 6.3.3 ADC Sampling Clock Input
      4. 6.3.4 Reference
        1. 6.3.4.1 Internal Reference Voltage
        2. 6.3.4.2 External Reference Voltage
      5. 6.3.5 Sample Synchronization
      6. 6.3.6 Data Interface
        1. 6.3.6.1 Data Clock Output
        2. 6.3.6.2 ADC Output Data Randomizer
        3. 6.3.6.3 Test Patterns for Data Interface
          1. 6.3.6.3.1 Fixed Pattern
          2. 6.3.6.3.2 Digital Ramp
          3. 6.3.6.3.3 Alternating Test Pattern
    4. 6.4 Device Functional Modes
      1. 6.4.1 Power-Down
      2. 6.4.2 Reset
      3. 6.4.3 Initialization Sequence
      4. 6.4.4 Normal Operation
    5. 6.5 Programming
      1. 6.5.1 Register Write
      2. 6.5.2 Register Read
      3. 6.5.3 Multiple Devices: Daisy-Chain Topology for SPI Configuration
        1. 6.5.3.1 Register Write With Daisy-Chain
        2. 6.5.3.2 Register Read With Daisy-Chain
  8. 7 Register Map
    1. 7.1 Register Bank 0
    2. 7.2 Register Bank 1
    3. 7.3 Register Bank 2
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Parametric Measurement Unit (PMU)
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
      4. 8.2.4 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.1 Analog Inputs

The ADS981x incorporates dual, simultaneous-sampling, 18-bit successive approximation register (SAR) analog-to-digital converters (ADCs). Each ADC is connected to four analog input channels through a multiplexer. The device has a total of eight analog input pairs. The ADC digitizes the voltage difference between the analog input pairs AINxP – AINxM. Figure 6-1 shows the simplified circuit schematic for each analog input channel, including the input clamp protection circuit, PGA, low-pass filter, multiplexer, high-speed ADC driver, and a precision 18-bit SAR ADC.

ADS9815 ADS9817 Front-End Circuit Schematic for the Selected Analog Input Channel Figure 6-1 Front-End Circuit Schematic for the Selected Analog Input Channel