JAJSHW2A August   2019  – April 2020 DRV425-Q1

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 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 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 Fluxgate Sensor Front-End
        1. 8.3.1.1 Fluxgate Sensor
        2. 8.3.1.2 Bandwidth
        3. 8.3.1.3 Differential Driver for the Internal Compensation Coil
        4. 8.3.1.4 Magnetic Field Range, Overrange Indicator, and Error Flag
      2. 8.3.2 Shunt-Sense Amplifier
      3. 8.3.3 Voltage Reference
      4. 8.3.4 Low-Power Operation
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Linear Position Sensing
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Current Sensing in Busbars
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Decoupling
    2. 10.2 Power-On Start-Up and Brownout
    3. 10.3 Power Dissipation
      1. 10.3.1 Thermal Pad
  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

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

9.2.2 Current Sensing in Busbars

In existing applications that use busbars for power distribution, closed-loop current modules are usually used to accurately measure and control the current. These modules are usually bulky because of the required large magnetic core. Additionally, because the compensation current generated inside the module is proportional to the usually high busbar current, the power dissipation of this solution is usually as high as several watts.

Figure 71 shows an alternative approach with two DRV425-Q1 devices. If a hole is drilled in the middle of the busbar, the current is split in two equal parts that generate magnetic field gradients with opposite directions inside the hole. These magnetic fields are termed BR and BL in Figure 72. The opposite fields cancel each other out in the middle of the hole. The high sensitivity and linearity of two DRV425-Q1 devices positioned at the same distance from the middle of the hole allow the small opposite fields to be sensed and the current measured with high-accuracy levels. The differential measurement rejects outside fields that generate a common-mode error that is subtracted at the output.

DRV425-Q1 drv425-q1-drv425-q1-based-busbar-current-sensing.gifFigure 71. Current Sensing in Busbars
DRV425-Q1 drv425-q1-magnetic-field-distribution-inside-a-busbar-hole.gifFigure 72. Magnetic Field Distribution Inside a Busbar Hole