ZHCSGP3D September   2017  – December 2018 OPA2837 , OPA837

PRODUCTION DATA.  

  1. 1 特性
  2. 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. 3 说明
    1.     Device Images
  4. 4 修订历史记录
  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: 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. 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. 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. 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

8.1.7 Differential to Single-Ended Amplifier

Figure 78 shows a differential amplifier that converts differential signals to single-ended in a single stage and provides gain (or attenuation) and level shifting. This circuit can be used in applications such as a line receiver for converting a differential signal from a Cat5 cable to a single-ended output signal.

OPA837 OPA2837 dif_sng_amp_sbos673.gifFigure 78. Differential to Single-Ended Amplifier

The output of the amplifier can be calculated according to Equation 9 if VIN+ = VCM + VSIG+ and VIN– = VCM + VSIG–.

Equation 9. OPA837 OPA2837 EQ3_vout3_los713.gif

The signal gain of the circuit is shown in Equation 10, VCM is rejected, and VREF provides a level shift or reference voltage around which the output signal swings. The single-ended output signal is in-phase with the noninverting input signal. VREF is often ground when split supplies are used on the op amp.

Equation 10. OPA837 OPA2837 Iline3_G3_los713.gif

Line termination can be accomplished by adding a shunt resistor across the VIN+ and VIN– inputs. The differential impedance is the shunt resistance in parallel with the input impedance of the amplifier circuit, which is usually much higher. For low gain and low line impedance, the resistor value to add is approximately the impedance of the line. For example, if a 100-Ω Cat5 cable is used with a gain of 1 V/V amplifier and RF = RG = 2 kΩ, adding a 100-Ω shunt across the input gives a differential impedance of 99 Ω, which is an adequate match for most applications.

For best CMRR performance, resistors must be matched. Assuming CMRR ≈ the resistor tolerance, a 0.1% tolerance provides approximately 60-dB CMRR.