JAJSF79F March   2002  – April 2018 OPA2357 , OPA357

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 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics: VS = +2.7-V to +5.5-V Single-Supply
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  OPAx357 Comparison
      2. 7.3.2  Operating Voltage
      3. 7.3.3  Enable Function
      4. 7.3.4  Rail-to-Rail Input
      5. 7.3.5  Rail-to-Rail Output
      6. 7.3.6  Output Drive
      7. 7.3.7  Video
      8. 7.3.8  Wideband Video Multiplexing
      9. 7.3.9  Driving Analog-to-Digital Converters
      10. 7.3.10 Capacitive Load and Stability
      11. 7.3.11 Wideband Transimpedance Amplifier
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Transimpedance Amplifier
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 OPAx357 Design Procedure
            1. 8.2.1.2.2.1 Optimizing the Transimpedance Circuit
        3. 8.2.1.3 Application Curve
      2. 8.2.2 High-Impedance Sensor Interface
      3. 8.2.3 Driving ADCs
      4. 8.2.4 Active Filter
  9. 9 Power Supply Recommendations
    1. 9.1 Power Dissipation
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 開発サポート
        1. 11.1.1.1 WEBENCH®ツールによるカスタム設計
    2. 11.2 ドキュメントのサポート
      1. 11.2.1 関連資料
    3. 11.3 関連リンク
    4. 11.4 ドキュメントの更新通知を受け取る方法
    5. 11.5 コミュニティ・リソース
    6. 11.6 商標
    7. 11.7 静電気放電に関する注意事項
    8. 11.8 Glossary
  12. 12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

8.2.2 High-Impedance Sensor Interface

Many sensors have high source impedances that can range up to 10 MΩ, or even higher. The output signal of sensors often must be amplified or otherwise conditioned by an amplifier. The input bias current of this amplifier can load the sensor output and cause a voltage drop across the source resistance, as shown in Figure 44, where (V(+INx) = VS – I(BIAS) × R(S)). The last term, I(BIAS) × R(S), shows the voltage drop across R(S). To prevent errors introduced to the system as a result of this voltage, use an op amp with low input bias current and high-impedance sensors. This low current keeps the error contribution by I(BIAS) × R(S) less than the input voltage noise of the amplifier, so that the amplifier does not become the dominant noise factor. The OPAx357 family of devices series of op amps feature low input bias current (typically 200 fA), and are therefore designed for such applications.

OPA357 OPA2357 ai_noise_ibias_sbos492.gifFigure 44. Noise as a Result of I(BIAS)