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

8.5.1.5 Data Transfer Protocol

Figure 34 shows the format of the data transfer. The master initiates all transactions with the ADS1219 by generating a START (S) condition. A high-to-low transition on the SDA line while SCL is high defines a START condition. The bus is considered to be busy after the START condition.

Following the START condition, the master sends the 7-bit slave address corresponding to the address of the ADS1219 that the master wants to communicate with. The master then sends an eighth bit that is a data direction bit (R/W). An R/W bit of 0 indicates a write operation, and an R/W bit of 1 indicates a read operation. After the R/W bit, the master generates a ninth SCLK pulse and releases the SDA line to allow the ADS1219 to acknowledge (ACK) the reception of the slave address by pulling SDA low. In case the device does not recognize the slave address, the ADS1219 holds SDA high to indicate a not acknowledge (NACK) signal.

Next follows the data transmission. If the transaction is a read (R/W = 1), the ADS1219 outputs data on SDA. If the transaction is a write (R/W = 0), the host outputs data on SDA. Data are transferred byte-wise, most significant bit (MSB) first. The number of bytes that can be transmitted per transfer is unrestricted. Each byte must be acknowledged (via the ACK bit) by the receiver. If the transaction is a read, the master issues the ACK. If the transaction is a write, the ADS1219 issues the ACK.

The master terminates all transactions by generating a STOP (P) condition. A low-to-high transition on the SDA line while SCL is high defines a STOP condition. The bus is considered free again tBUF (bus-free time) after the STOP condition.

ADS1219 ai_I2C_data_transfer_bas751.gifFigure 34. I2C Data Transfer Format