ZHCSFV2D December   2016  – December 2018 OPA187 , OPA2187 , OPA4187

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      OPAx187 具有高精度低侧电流测量功能
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
    1.     Pin Functions: OPA187
    2.     Pin Functions: OPA2187
    3.     Pin Functions: OPA4187
  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: OPA187
    5. 6.5 Thermal Information: OPA2187
    6. 6.6 Thermal Information: OPA4187
    7. 6.7 Electrical Characteristics: High-Voltage Operation
    8. 6.8 Electrical Characteristics: Low-Voltage Operation
    9. 6.9 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 Operating Characteristics
      2. 7.3.2 Phase-Reversal Protection
      3. 7.3.3 Input Bias Current Clock Feedthrough
      4. 7.3.4 Internal Offset Correction
      5. 7.3.5 EMI Rejection
      6. 7.3.6 Capacitive Load and Stability
      7. 7.3.7 Electrical Overstress
    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 High-Side Voltage-to-Current (V-I) Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Discrete INA + Attenuation for ADC With 3.3-V Supply
      3. 8.2.3 Bridge Amplifier
      4. 8.2.4 Low-Side Current Monitor
      5. 8.2.5 Programmable Power Supply
      6. 8.2.6 RTD Amplifier With Linearization
  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 器件支持
      1. 11.1.1 开发支持
        1. 11.1.1.1 TINA-TI™（免费软件下载）
        2. 11.1.1.2 TI 高精度设计
        3. 11.1.1.3 WEBENCH® Filter Designer
    2. 11.2 文档支持
      1. 11.2.1 相关文档
    3. 11.3 相关链接
    4. 11.4 接收文档更新通知
    5. 11.5 社区资源
    6. 11.6 商标
    7. 11.7 静电放电警告
    8. 11.8 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

8.2.1.2 Detailed Design Procedure

The V-I transfer function of the circuit is based on the relationship between the input voltage, VIN, and the three current sensing resistors, RS1, RS2, and RS3. The relationship between VIN and RS1 determines the current that flows through the first stage of the design. The current gain from the first stage to the second stage is based on the relationship between RS2 and RS3.

This application benefits from an operational amplifier with low offset voltage, low temperature drift, and rail-to-rail output. The OPAx187 CMOS operational amplifier is a high-precision, ultra-low offset, ultra-low drift amplifier, optimized for wide-voltage, single-supply operation, with an output swing to within 5 mV of the positive rail. The OPAx187 family uses chopping techniques to provide low initial offset voltage and near-zero drift over time and temperature. Low offset voltage and low drift reduce the offset error in the system, making this device appropriate for precise dc control. The rail-to-rail output stage of the OPAx187 makes sure that the output swing of the operational amplifier is able to fully control the gate of the MOSFET devices within the supply rails.

A detailed error analysis, design procedure, and additional measured results are given in reference design TIPD102, a step-by-step process to design a High-Side Voltage-to-Current (V-I) Converter.

OPA187 OPA2187 OPA4187 apps_tipd_logo_bas557.gif
For step-by-step design procedure, circuit schematics, bill of materials, PCB files, simulation results, and test results, refer to TI Precision Design TIPD102, High-Side Voltage-to-Current (V-I) Converter (SLAU502).