SBAS580D May   2013  – March 2018 ADS7250 , ADS7850 , ADS8350

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Functional Block Diagram
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics: All Devices
    6. 6.6  Electrical Characteristics: ADS7250
    7. 6.7  Electrical Characteristics: ADS7850
    8. 6.8  Electrical Characteristics: ADS8350
    9. 6.9  Timing Requirements
    10. 6.10 Switching Characteristics
    11. 6.11 Typical Characteristics: ADS7250
    12. 6.12 Typical Characteristics: ADS7850
    13. 6.13 Typical Characteristics: ADS8350
    14. 6.14 Typical Characteristics: All Devices
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Reference
      2. 7.3.2 Analog Input
        1. 7.3.2.1 Analog Input Full-Scale Range
      3. 7.3.3 ADC Transfer Function
    4. 7.4 Device Functional Modes
      1. 7.4.1 Serial Interface
      2. 7.4.2 Short-Cycling, Frame Abort, and Reconversion Feature
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 DAQ Circuit: Maximum SINAD for a 10-kHz Input Signal at 750-kSPS Throughput
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 ADC Reference Driver
          2. 8.2.1.2.2 ADC Input Driver
            1. 8.2.1.2.2.1 Input Amplifier Selection
            2. 8.2.1.2.2.2 Antialiasing Filter
        3. 8.2.1.3 Application Curve
      2. 8.2.2 DAQ Circuit: Maximum SINAD for a 100-kHz Input Signal at 750-kSPS Throughput
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 ADC Reference Driver
          2. 8.2.2.2.2 ADC Input Driver
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Related Links
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2 Analog Input

The devices support pseudo-differential analog input signals. These inputs are sampled and converted simultaneously by the two ADCs (ADC_A and ADC_B). ADC_A samples and converts (VAINP_A – VAINM_A), and ADC_B samples and converts (VAINP_B – VAINM_B).

Figure 50a and Figure 50b show equivalent circuits for the ADC_A and ADC_B analog input pins, respectively. RS (typically 50 Ω) represents the on-state sampling switch resistance, and CSAMPLE represents the device sampling capacitor (typically 40 pF).

ADS8350 ADS7850 ADS7250 ai_input_bas580.gifFigure 50. Equivalent Circuit for Analog Input Pins