ZHCSGP3D September   2017  – December 2018 OPA2837 , OPA837

PRODUCTION DATA.  

  1. 特性
  2. 应用
    1.     具有真正接地输入和输出范围的低功耗、低噪声、精密单端 SAR ADC 驱动器
  3. 说明
    1.     Device Images
  4. 修订历史记录
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information: OPA837
    5. 6.5  Thermal Information: OPA2837
    6. 6.6  Electrical Characteristics: VS = 5 V
    7. 6.7  Electrical Characteristics: VS = 3 V
    8. 6.8  Typical Characteristics: VS = 5.0 V
    9. 6.9  Typical Characteristics: VS = 3.0 V
    10. 6.10 Typical Characteristics: ±2.5-V to ±1.5-V Split Supply
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 OPA837 Comparison
      2. 7.3.2 Input Common-Mode Voltage Range
      3. 7.3.3 Output Voltage Range
      4. 7.3.4 Power-Down Operation
      5. 7.3.5 Low-Power Applications and the Effects of Resistor Values on Bandwidth
      6. 7.3.6 Driving Capacitive Loads
    4. 7.4 Device Functional Modes
      1. 7.4.1 Split-Supply Operation (±1.35 V to ±2.7 V)
      2. 7.4.2 Single-Supply Operation (2.7 V to 5.4 V)
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  Noninverting Amplifier
      2. 8.1.2  Inverting Amplifier
      3. 8.1.3  Output DC Error Calculations
      4. 8.1.4  Output Noise Calculations
      5. 8.1.5  Instrumentation Amplifier
      6. 8.1.6  Attenuators
      7. 8.1.7  Differential to Single-Ended Amplifier
      8. 8.1.8  Differential-to-Differential Amplifier
      9. 8.1.9  Pulse Application With Single-Supply Circuit
      10. 8.1.10 ADC Driver Performance
    2. 8.2 Typical Applications
      1. 8.2.1 Active Filters
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Implementing a 2:1 Active Multiplexer
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
      3. 8.2.3 1-Bit PGA Operation
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 文档支持
      1. 11.1.1 相关文档
    2. 11.2 相关链接
    3. 11.3 接收文档更新通知
    4. 11.4 社区资源
    5. 11.5 商标
    6. 11.6 静电放电警告
    7. 11.7 术语表
  12. 12机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

Output Noise Calculations

The unity-gain stable, voltage-feedback OPAx837 op amp offers among the lowest input voltage and current noise terms for any device with a supply current less than 0.7 mA. Figure 76 shows the op amp noise analysis model that includes all noise terms. In this model, all noise terms are shown as noise voltage or current density terms in nV/√Hz or pA/√Hz.

OPA837 OPA2837 ai_noise_model_sbos673.gifFigure 76. Op Amp Noise Analysis Model

The total output spot noise voltage is computed as the square root of the squared contributing terms to the output noise voltage. This computation is adding all the contributing noise powers at the output by superposition, then taking the square root to return to a spot noise voltage. The last term includes the noise for both the RG and RF resistors. Equation 5 shows the general form for this output noise voltage using the terms presented in Figure 76.

Equation 5. OPA837 OPA2837 eq_07_sbos303.gif

Dividing this expression by the noise gain (NG = 1 + RF / RG), as shown in Equation 6, gives the equivalent input referred spot noise voltage at the noninverting input.

Equation 6. OPA837 OPA2837 eq_08_sbos303.gif

Using the resistor values listed in Table 2 with RS = 0 Ω results in a constant input-referred voltage noise of < 7 nV/√Hz. Reducing the resistor values can reduce this noise value towards the 4.7 nV/√Hz intrinsic to the OPA837. As shown in Equation 5, adding the RS for bias current cancellation in noninverting mode adds the noise from the RS to the total output noise. In inverting mode, bypass the RS bias current cancellation resistor with a capacitor for the best noise performance. For more details on op amp noise analysis, see the Noise Analysis for High-Speed Op Amps application report.