JAJSMH3B December   1997  – November 2024 OPA134 , OPA2134 , OPA4134

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 - OPA134
    5. 5.5 Thermal Information - OPA2134
    6. 5.6 Thermal Information - OPA4134
    7. 5.7 Electrical Characteristics
    8. 5.8 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Feature Description
      1. 6.2.1 Total Harmonic Distortion
      2. 6.2.2 Distortion Measurements
      3. 6.2.3 Source Impedance and Distortion
      4. 6.2.4 Phase Reversal Protection
      5. 6.2.5 Output Current Limit
    3. 6.3 Functional Block Diagram
    4. 6.4 Device Functional Modes
      1. 6.4.1 Noise Performance
  8. Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Operating Voltage
      2. 7.1.2 Offset Voltage Trim
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 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
        1. 8.1.1.1 Analog Filter Designer
        2. 8.1.1.2 TINA-TI™シミュレーション ソフトウェア (無償ダウンロード)
        3. 8.1.1.3 TI のリファレンス・デザイン
    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

Noise Performance

Circuit noise is determined by the thermal noise of external resistors and operational amplifier noise. Operational amplifier noise is described by two parameters: noise voltage and noise current. The total noise is quantified by the equation:

Equation 1. Vn(total)=en2+( inRS)2+4kTRS

With low source impedance, the current noise term is insignificant and voltage noise dominates the noise performance. At high source impedance, the current noise term becomes the dominant contributor.

Low-noise bipolar operational amplifiers such as the OPA27 and OPA37 provide low voltage noise at the expense of a higher current noise. However, OPAx134 series operational amplifiers provide both low voltage noise and low current noise. This provides optimum noise performance over a wide range of sources, including reactive source impedances; refer to Figure 5-6. Above 2kΩ source resistance, the operational amplifier contributes little additional noise; the voltage and current terms in the total noise equation become insignificant and the source resistance term dominates. Below 2kΩ, operational amplifier voltage noise dominates over the resistor noise, but compares favorably with other audio operational amplifiers such as the OP176.