SBAS924A July   2018  – November 2018 ADS1219

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Voltage, Current, and Temperature Monitoring Application
  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
    6. 6.6 I2C Timing Requirements
    7. 6.7 I2C Switching Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Noise Performance
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Multiplexer
      2. 8.3.2 Rail-to-Rail Input Buffers and Programmable Gain Stage
      3. 8.3.3 Voltage Reference
      4. 8.3.4 Modulator and Internal Oscillator
      5. 8.3.5 Digital Filter
      6. 8.3.6 Conversion Times
      7. 8.3.7 Offset Calibration
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Up and Reset
        1. 8.4.1.1 Power-On Reset
        2. 8.4.1.2 RESET Pin
        3. 8.4.1.3 Reset by Command
      2. 8.4.2 Conversion Modes
        1. 8.4.2.1 Single-Shot Conversion Mode
        2. 8.4.2.2 Continuous Conversion Mode
      3. 8.4.3 Power-Down Mode
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
        1. 8.5.1.1 I2C Address
        2. 8.5.1.2 Serial Clock (SCL) and Serial Data (SDA)
        3. 8.5.1.3 Data Ready (DRDY)
        4. 8.5.1.4 Interface Speed
        5. 8.5.1.5 Data Transfer Protocol
        6. 8.5.1.6 I2C General Call (Software Reset)
        7. 8.5.1.7 Timeout
      2. 8.5.2 Data Format
      3. 8.5.3 Commands
        1. 8.5.3.1 Command Latching
        2. 8.5.3.2 RESET (0000 011x)
        3. 8.5.3.3 START/SYNC (0000 100x)
        4. 8.5.3.4 POWERDOWN (0000 001x)
        5. 8.5.3.5 RDATA (0001 xxxx)
        6. 8.5.3.6 RREG (0010 0rxx)
        7. 8.5.3.7 WREG (0100 00xx dddd dddd)
      4. 8.5.4 Reading Data and Monitoring for New Conversion Results
    6. 8.6 Register Map
      1. 8.6.1 Configuration and Status Registers
      2. 8.6.2 Register Descriptions
        1. 8.6.2.1 Configuration Register (address = 0h) [reset = 00h]
          1. Table 10. Configuration Register Field Descriptions
        2. 8.6.2.2 Status Register (address = 1h) [reset = 00h]
          1. Table 11. Status Register Field Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Interface Connections
      2. 9.1.2 Connecting Multiple Devices on the Same I2C Bus
      3. 9.1.3 Unused Inputs and Outputs
      4. 9.1.4 Analog Input Filtering
      5. 9.1.5 External Reference and Ratiometric Measurements
      6. 9.1.6 Establishing Proper Limits on the Absolute Input Voltage
      7. 9.1.7 Pseudo Code Example
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Voltage Monitoring
        2. 9.2.2.2 High-Side Current Measurement
        3. 9.2.2.3 Thermistor Measurement
        4. 9.2.2.4 Register Settings
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
    1. 10.1 Power-Supply Sequencing
    2. 10.2 Power-Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.5.3.5 RDATA (0001 xxxx)

The RDATA command loads the output shift register with the most recent conversion result. Reading conversion data must be performed as shown in Figure 36 by using two I2C communication frames. The first frame is an I2C write operation where the R/W bit at the end of the address byte is 0 to indicate a write. In this frame, the host sends the RDATA command to the ADS1219. The second frame is an I2C read operation where the R/W bit at the end of the address byte is 1 to indicate a read. The ADS1219 reports the latest ADC conversion data in this second I2C frame. If a conversion finishes in the middle of the RDATA command byte, the state of the DRDY pin at the end of the read operation signals whether the old or the new result is loaded. If the old result is loaded, DRDY stays low, indicating that the new result is not read out. The new conversion result loads when DRDY is high.

ADS1219 ai_RDATA_command_bas751.gifFigure 36. Read Conversion Data Sequence