JAJSE97D June   2017  – May 2019 DAC8740H , DAC8741H

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin Functions: DAC8740H
    2.     Pin Functions: DAC8741H
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  HART Modulator
      2. 9.3.2  HART Demodulator
      3. 9.3.3  FOUNDATION Fieldbus or PROFIBUS PA Manchester Encoder
      4. 9.3.4  FOUNDATION Fieldbus or PROFIBUS PA Manchester Decoder
      5. 9.3.5  Internal Reference
      6. 9.3.6  Clock Configuration
      7. 9.3.7  Reset and Power-Down
      8. 9.3.8  Full-Duplex Mode
      9. 9.3.9  I/O Selection
      10. 9.3.10 Jabber Inhibitor
    4. 9.4 Device Functional Modes
      1. 9.4.1 UART Interfaced HART
      2. 9.4.2 UART Interfaced FOUNDATION Fieldbus or PROFIBUS PA
      3. 9.4.3 SPI Interfaced HART
      4. 9.4.4 SPI Interfaced FOUNDATION Fieldbus or PROFIBUS PA
      5. 9.4.5 Digital Interface
        1. 9.4.5.1 UART
          1. 9.4.5.1.1 UART Carrier Detect
        2. 9.4.5.2 SPI
          1. 9.4.5.2.1 SPI Cyclic Redundancy Check
          2. 9.4.5.2.2 SPI Interrupt Request
    5. 9.5 Register Maps
      1. 9.5.1 CONTROL Register (Offset = 2h) [reset = 0x8042]
        1. Table 9. CONTROL Register Field Descriptions
      2. 9.5.2 RESET Register (Offset = 7h) [reset = 0x0000]
        1. Table 10. RESET Register Field Descriptions
      3. 9.5.3 MODEM_STATUS Register (Offset = 20h) [reset = 0x0000]
        1. Table 11. MODEM_STATUS Register Field Descriptions
      4. 9.5.4 MODEM_IRQ_MASK Register (Offset = 21h) [reset = 0x0024]
        1. Table 12. MODEM_IRQ_MASK Register Field Descriptions
      5. 9.5.5 MODEM_CONTROL Register (Offset = 22h) [reset = 0x0048]
        1. Table 13. MODEM_CONTROL Register Field Descriptions
      6. 9.5.6 FIFO_D2M Register (Offset = 23h) [reset = 0x0200]
        1. Table 14. FIFO_D2M Register Field Descriptions
      7. 9.5.7 FIFO_M2D Register (Offset = 24h) [reset = 0x0200]
        1. Table 15. FIFO_M2D Register Field Descriptions
      8. 9.5.8 FIFO_LEVEL_SET Register (Offset = 25h) [reset = 0x0000]
        1. Table 16. FIFO_LEVEL_SET Register Field Descriptions
      9. 9.5.9 PAFF_JABBER Register (Offset = 27h) [reset = 0x0000]
        1. Table 17. PAFF_JABBER Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Design Recommendations
      2. 10.1.2 Selecting the Crystal or Resonator
      3. 10.1.3 Included Functions and Filter Selection
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 DAC8740H HART Modem
        2. 10.2.2.2 2-Wire Current Loop
        3. 10.2.2.3 Regulator
        4. 10.2.2.4 DAC
        5. 10.2.2.5 Amplifiers
        6. 10.2.2.6 Diodes
        7. 10.2.2.7 Passives
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  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 ドキュメントのサポート
      1. 13.1.1 関連資料
    2. 13.2 関連リンク
    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

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.4.1 UART Interfaced HART

When interfacing the HART modem via the UART interface, the device can be thought of as a simple UART-to-HART or HART-to-UART direct feedthrough converter. The UART data is transmitted and received at 1200 baud, which is matched to the HART FSK input and output signals.

The HART communication protocol is a half-duplex protocol which means that either the modulator or demodulator is active, and never simultaneously enabled. The device arbitrates over which component of the modem is active at all times based on activity on the HART bus. Bus activity is interfaced to the host controller through the CD and RTS pins.

By default when RTS is high the demodulator is active and the modulator is inactive. When a valid carrier is detected and data is being received by the modem, the CD pin is toggled high and binary UART data is provided at the output. If a request to send is issued by toggling the RTS pin low while CD is high, the demodulator remains at priority and any data provided at the UART input is ignored. When CD is low no valid carrier is present and when RTS is brought low the modulator is activated and UART input data is latched into the modulator and placed onto the HART bus.