JAJSMX0 September   2020 INA848

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 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 Topology
      2. 8.3.2 Input Common-Mode Range
      3. 8.3.3 Input Protection
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Filter Pin
        1. 9.1.1.1 RC Filter Network
        2. 9.1.1.2 RLC Filter Network
      2. 9.1.2 Input Bias Current Return Path
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Reference Pin
        2. 9.2.2.2 Noise Analysis
          1. 9.2.2.2.1 Reference Voltage Noise Contribution
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 サポート・リソース
    4. 12.4 Trademarks
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 用語集
  13. 13Mechanical, Packaging, and Orderable Information

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

8.3.3 Input Protection

The inputs of the INA848 device are individually protected for voltages up to ±20 V which is stated in Section 7.1. If these rating cannot be met, additional protection circuitry must be considered at the input pins to minimize the current flowing in case of fault.

During an input overvoltage condition, current flows through the input protection diodes into the power supplies; see Figure 8-3 . If the power supplies are unable to sink current, then Zener diode clamps (ZD1 and ZD2) must be placed on the power supplies to provide a current pathway to ground.

Figure 8-3 Input Current Path During an Overvoltage Condition

For an overvoltage condition, use an external resistor (RIN1, RIN2) to limit the current. The following equation gives the calculation for the protection resistors:

Equation 1. GUID-20200824-CA0I-PFSX-03RG-LVLMDS6TFDG1-low.gif

where:

  • V+IN is the maximum input voltage
  • +VS is the positive supply rail
  • IMAX is the maximum current allowed = 10 mA

Calclate RIN2 using the same method, substituting with V–IN, –VS, and –IMAX.

Any additional resistance to the input pins adds more noise to the system. For more details, see Section 9.2.2.2.