JAJSFM6A June   2018  – October 2018 ISO224

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 デバイス比較表
  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  Power Ratings
    6. 7.6  Insulation Specifications
    7. 7.7  Safety-Related Certifications
    8. 7.8  Safety Limiting Values
    9. 7.9  Electrical Characteristics
    10. 7.10 Switching Characteristics
    11. 7.11 Insulation Characteristics Curves
    12. 7.12 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Analog Input
      2. 8.3.2 Input Clamp Protection Circuit
      3. 8.3.3 Isolation Channel Signal Transmission
      4. 8.3.4 Fail-Safe Output
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 What to Do and What Not to Do
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 ドキュメントのサポート
      1. 12.1.1 関連資料
    2. 12.2 ドキュメントの更新通知を受け取る方法
    3. 12.3 コミュニティ・リソース
    4. 12.4 商標
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13メカニカル、パッケージ、および注文情報

8.3.2 Input Clamp Protection Circuit

As illustrated in the Functional Block Diagram, the ISO224 features an internal clamp protection circuit on the analog input IN. Using external protection circuits is recommended as a secondary protection scheme to protect the device against surges, ESD events, and electrical fast transient (EFT) conditions.

Figure 42 shows a typical current versus voltage characteristic curve for the input clamp. Limit either the voltage VIN at the input pin IN to the voltage range as defined in the Recommended Operating Conditions table or the input current to the limits as defined in the Absolute Maximum Ratings table.

ISO224 D007_SBAS642.gifFigure 42. I-V Curve of the Input Clamp Protection Circuit

Figure 43 shows a simple method to limit the input current with an external series resistor that is also used as part of the input low-pass filter.

ISO224 ai_clamp_bas738.gifFigure 43. Series Resistor-Based Input Current Limitation on the Analog Inputs of ISO224

The input overvoltage protection clamp on the ISO224 is intended to control transient excursions on the input pins. Leaving the device in a state such that the clamp circuit is activated for extended periods of time in normal or power-down mode is not recommended because this fault condition can degrade device performance and reliability.