SBASB68 August   2025 ADS9803

PRODMIX  

  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
      2. 6.3.2 ADC Transfer Function
      3. 6.3.3 ADC Sampling Clock Input
      4. 6.3.4 Synchronizing Multiple ADCs
      5. 6.3.5 Reference Voltage
      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 Data Averaging
        4. 6.3.6.4 Test Patterns for Data Interface
          1. 6.3.6.4.1 Fixed Pattern
          2. 6.3.6.4.2 Digital Ramp
          3. 6.3.6.4.3 Alternating Test Pattern
    4. 6.4 Device Functional Modes
      1. 6.4.1 Reset
      2. 6.4.2 Power-Down
      3. 6.4.3 Initialization Sequence
      4. 6.4.4 Normal Operation
      5. 6.4.5 Speed-Boost Mode
    5. 6.5 Programming
      1. 6.5.1 Register Write
      2. 6.5.2 Register Read
      3. 6.5.3 Multiple Devices in a 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 ADS9803 incorporates eight, simultaneous sampling, 20-bit successive approximation register (SAR) analog-to-digital converters (ADCs). 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. This figure also shows the input clamp protection circuit, programmable gain amplifier (PGA), low-pass filter, high-speed ADC driver, and a precision 20-bit SAR ADC. Typical SNR for analog input ranges vs input common-mode ranges are shown in Table 6-5 for low-bandwidth mode and Table 6-6 for wide-bandwidth mode.

ADS9801 ADS9803 Front-End Circuit Schematic for the Selected Analog Input Channel Figure 6-1 Front-End Circuit Schematic for the Selected Analog Input Channel