JAJSS82E August   2009  – July 2024 LPV521

PRODUCTION DATA  

  1.   1
  2. 特長
  3. アプリケーション
  4. 概要
  5. Pin Configuration and Functions
  6. Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
    4. 6.4 Device Functional Modes
      1. 6.4.1 Input Stage
      2. 6.4.2 Output Stage
  8. Applications and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Driving Capacitive Load
      2. 7.1.2 EMI Suppression
    2. 7.2 Typical Applications
      1. 7.2.1 60Hz Twin T-Notch Filter
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curve
      2. 7.2.2 Portable Gas Detection Sensor
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curve
      3. 7.2.3 High-Side Battery Current Sensing
        1. 7.2.3.1 Design Requirements
        2. 7.2.3.2 Detailed Design Procedure
        3. 7.2.3.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 ドキュメントの更新通知を受け取る方法
    4. 8.4 サポート・リソース
    5. 8.5 Trademarks
    6. 8.6 静電気放電に関する注意事項
    7. 8.7 用語集
  10. Revision History
  11. 10Mechanical, Packaging, and Orderable Information

EMI Suppression

The near-ubiquity of cellular, Bluetooth®, and Wi-Fi® signals and the rapid rise of sensing systems incorporating wireless radios make electromagnetic interference (EMI) an evermore important design consideration for precision signal paths. Though RF signals lie outside the op-amp band, RF carrier switching can modulate the dc offset of the op amp. Also some common RF modulation schemes can induce down-converted components. The added dc offset and the induced signals are amplified with the signal of interest and thus corrupt the measurement. The LPV521 uses on-chip filters to reject these unwanted RF signals at the inputs and power supply pins, thereby preserving the integrity of the precision signal path.

Twisted pair cabling and the active front-end common-mode rejection provide immunity against low-frequency noise (for example, 60Hz or 50Hz mains) but are ineffective against RF interference. Even a few centimeters of printed circuit board (PCB) trace and wiring for sensors located close to the amplifier can pick up significant 1GHz RF. The integrated EMI filters of the LPV521 reduce or eliminate external shielding and filtering requirements, thus increasing system robustness. A larger EMIRR means more rejection of the RF interference. For more information on EMIRR, see the AN-1698 A Specification for EMI Hardened Operational Amplifiers application report.