JAJSEX6B December   2017  – October 2019 INA381

PRODUCTION DATA.  

  1. 特長
  2. アプリケーション
  3. 概要
    1.     Device Images
      1.      代表的なアプリケーション
  4. 改訂履歴
  5. 概要(続き)
  6. Pin Configuration and Functions
    1.     Pin Functions
  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. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Wide Input Common-Mode Voltage Range
      2. 8.3.2 Precise Low-Side Current Sensing
      3. 8.3.3 High Bandwidth and Slew Rate
      4. 8.3.4 Alert Output
      5. 8.3.5 Adjustable Overcurrent Threshold
      6. 8.3.6 Comparator Hysteresis
    4. 8.4 Device Functional Modes
      1. 8.4.1 Alert Modes
        1. 8.4.1.1 Transparent Output Mode
        2. 8.4.1.2 Latch Output Mode
  9. Applications and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Select a Current-Sensing Resistor
        1. 9.1.1.1 Select a Current-Sensing Resistor: Example
      2. 9.1.2 Increase Comparator Hysteresis
      3. 9.1.3 Operation With Common-Mode Transients Greater Than 26 V
      4. 9.1.4 Input Filtering
    2. 9.2 Typical Applications
      1. 9.2.1 Bidirectional Window Comparator
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Solenoid Low-Side Current Sensing
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curve
  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 サポート・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

パッケージ・オプション

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ(パッケージ|ピン)
  • DGS|10
  • DSG|8
サーマルパッド・メカニカル・データ
発注情報

Select a Current-Sensing Resistor

The device measures the differential voltage developed across a resistor when current flows through the component to determine if the current being monitored exceeds a defined limit. This resistor is commonly referred to as a current-sensing resistor or a current-shunt resistor, with each term commonly used interchangeably. The flexible design of the device allows for measuring a wide differential input signal range across this current-sensing resistor.

Selecting the value of this current-sensing resistor is based primarily on two factors: the required accuracy of the current measurement and the allowable power dissipation across the current-sensing resistor. Larger voltages developed across this resistor allow for more accurate measurements to be made. Amplifiers have fixed internal errors that are largely dominated by the inherent input offset voltage. When the input signal decreases, these fixed internal amplifier errors become a larger portion of the measurement and increase the uncertainty in the measurement accuracy. When the input signal increases, the measurement uncertainty is reduced because the fixed errors are a smaller percentage of the signal being measured. Therefore, the use of larger-value, current-sensing resistors inherently improves measurement accuracy.

However, a system design trade-off must be evaluated through use of larger input signals for improving the measurement accuracy. Increasing the current-sense resistor value results in increased power dissipation across the current-sensing resistor. Increasing the value of the current-shunt resistor increases the differential voltage developed across the resistor when current passes through the component. This increase in voltage across the resistor increases the power that the resistor must be able to dissipate. Decreasing the value of the current-shunt resistor value reduces the power dissipation requirements of the resistor, but increases the measurement errors resulting from the decreased input signal. Selecting the optimal value for the shunt resistor requires factoring both the accuracy requirement for the specific application and the allowable power dissipation of this component.

An increasing number of very low ohmic-value resistors are becoming more widely available with values reaching down as low as 1 mΩ or lower with power dissipations of up to 5 W that enable large currents to be accurately monitored with sensing resistors.