JAJSFR6A July   2018  – November 2018 ADS1219

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      電圧、電流、および温度監視アプリケーション
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Timing Requirements
    7. 7.7 I2C Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Noise Performance
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Multiplexer
      2. 9.3.2 Rail-to-Rail Input Buffers and Programmable Gain Stage
      3. 9.3.3 Voltage Reference
      4. 9.3.4 Modulator and Internal Oscillator
      5. 9.3.5 Digital Filter
      6. 9.3.6 Conversion Times
      7. 9.3.7 Offset Calibration
    4. 9.4 Device Functional Modes
      1. 9.4.1 Power-Up and Reset
        1. 9.4.1.1 Power-On Reset
        2. 9.4.1.2 RESET Pin
        3. 9.4.1.3 Reset by Command
      2. 9.4.2 Conversion Modes
        1. 9.4.2.1 Single-Shot Conversion Mode
        2. 9.4.2.2 Continuous Conversion Mode
      3. 9.4.3 Power-Down Mode
    5. 9.5 Programming
      1. 9.5.1 I2C Interface
        1. 9.5.1.1 I2C Address
        2. 9.5.1.2 Serial Clock (SCL) and Serial Data (SDA)
        3. 9.5.1.3 Data Ready (DRDY)
        4. 9.5.1.4 Interface Speed
        5. 9.5.1.5 Data Transfer Protocol
        6. 9.5.1.6 I2C General Call (Software Reset)
        7. 9.5.1.7 Timeout
      2. 9.5.2 Data Format
      3. 9.5.3 Commands
        1. 9.5.3.1 Command Latching
        2. 9.5.3.2 RESET (0000 011x)
        3. 9.5.3.3 START/SYNC (0000 100x)
        4. 9.5.3.4 POWERDOWN (0000 001x)
        5. 9.5.3.5 RDATA (0001 xxxx)
        6. 9.5.3.6 RREG (0010 0rxx)
        7. 9.5.3.7 WREG (0100 00xx dddd dddd)
      4. 9.5.4 Reading Data and Monitoring for New Conversion Results
    6. 9.6 Register Map
      1. 9.6.1 Configuration and Status Registers
      2. 9.6.2 Register Descriptions
        1. 9.6.2.1 Configuration Register (address = 0h) [reset = 00h]
          1. Table 10. Configuration Register Field Descriptions
        2. 9.6.2.2 Status Register (address = 1h) [reset = 00h]
          1. Table 11. Status Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Interface Connections
      2. 10.1.2 Connecting Multiple Devices on the Same I2C Bus
      3. 10.1.3 Unused Inputs and Outputs
      4. 10.1.4 Analog Input Filtering
      5. 10.1.5 External Reference and Ratiometric Measurements
      6. 10.1.6 Establishing Proper Limits on the Absolute Input Voltage
      7. 10.1.7 Pseudo Code Example
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Voltage Monitoring
        2. 10.2.2.2 High-Side Current Measurement
        3. 10.2.2.3 Thermistor Measurement
        4. 10.2.2.4 Register Settings
      3. 10.2.3 Application Curve
  11. 11Power Supply Recommendations
    1. 11.1 Power-Supply Sequencing
    2. 11.2 Power-Supply Decoupling
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 デバイス・サポート
      1. 13.1.1 デベロッパー・ネットワークの製品に関する免責事項
    2. 13.2 ドキュメントのサポート
      1. 13.2.1 関連資料
    3. 13.3 ドキュメントの更新通知を受け取る方法
    4. 13.4 コミュニティ・リソース
    5. 13.5 商標
    6. 13.6 静電気放電に関する注意事項
    7. 13.7 Glossary
  14. 14メカニカル、パッケージ、および注文情報

9.5.4 Reading Data and Monitoring for New Conversion Results

Conversion data are read by issuing the RDATA command. The ADS1219 responds to the RDATA command with the latest conversion result. There are two ways to monitor for new conversion data.

One way is to monitor for the falling edge of the DRDY signal. When DRDY falls low, a new conversion result is available for retrieval using the RDATA command. Figure 39 shows the timing diagram for collecting data using the DRDY signal to indicate new data.

ADS1219 ai_RDATA_using_DRDY_Pin_bas751.gifFigure 39. Using the DRDY Pin to Check for New Conversion Data

Another way to monitor for a new conversion result is to periodically read the DRDY bit in the status register. If set, the DRDY bit indicates that a new conversion result is ready for retrieval. The host can subsequently issue an RDATA command to retrieve the data. The rate at which the host polls the ADS1219 for new data must be at least as fast as the data rate in continuous conversion mode to prevent the host from missing a conversion result.

If a new conversion result becomes ready during an I2C transmission, the transmission is not corrupted. The new data are loaded into the output shift register upon the following RDATA command.

Figure 40 shows the timing diagram for collecting data using the DRDY bit in the status register to indicate new data.

ADS1219 ai_RDATA_using_DRDY_Bit_bas924.gifFigure 40. Using the DRDY Bit to Check for New Conversion Data