SBAS350H June   2005  – June 2025 ADS1232 , ADS1234

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 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Noise Performance
  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 (AINPX, AINNX)
      2. 7.3.2  Temperature Sensor (ADS1232 Only)
      3. 7.3.3  Low-Noise PGA
        1. 7.3.3.1 PGA Bypass Capacitor
      4. 7.3.4  Voltage Reference Inputs (REFP, REFN)
      5. 7.3.5  Clock Sources
      6. 7.3.6  Digital Filter Frequency Response
      7. 7.3.7  Settling Time
      8. 7.3.8  Data Rate
      9. 7.3.9  Data Format
      10. 7.3.10 Data Ready and Data Output (DRDY/DOUT)
      11. 7.3.11 Serial Clock Input (SCLK)
      12. 7.3.12 Data Retrieval
    4. 7.4 Device Functional Modes
      1. 7.4.1 Offset Calibration Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Standby Mode With Offset-Calibration
      4. 7.4.4 Power-Down Mode
      5. 7.4.5 Power-Up Sequence
      6. 7.4.6 Summary of Serial Interface Waveforms
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power-Supply Decoupling
    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

7.3.3.1 PGA Bypass Capacitor

By applying a 0.1µF external capacitor (CEXT) across two PGA output pins (pins 9 and 10 and the combination of the internal 2kΩ resistor (RINT), a low-pass filter with a corner frequency of 720Hz is created to band limit the signal path prior to the modulator input. This low-pass filter serves two purposes. First, the input signal is band-limited to prevent aliasing, as well as to filter high-frequency noise. Second, the low-pass filter attenuates the chopping residue from the PGA (for gains of 64 and 128 only) to improve temperature drift performance. High-quality capacitors (such as high-k ceramic or tantalum capacitors) are not required for a general application. However, high-quality capacitors, such as C0G dielectric ceramic or poly, are recommended for high-linearity applications.