ZHCS968B June   2012  – November 2017 INA827

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     简化电路原理图
  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
    5. 6.5 Electrical Characteristics
  7. 7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Setting the Gain
        1. 8.3.1.1 Gain Drift
      2. 8.3.2  Offset Trimming
      3. 8.3.3  Input Common-Mode Range
      4. 8.3.4  Inside the INA827
      5. 8.3.5  Input Protection
      6. 8.3.6  Input Bias Current Return Path
      7. 8.3.7  Reference Pin
      8. 8.3.8  Dynamic Performance
      9. 8.3.9  Operating Voltage
        1. 8.3.9.1 Low-Voltage Operation
      10. 8.3.10 Error Sources
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 CMRR vs Frequency
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 文档支持
      1. 12.1.1 相关文档
    2. 12.2 接收文档更新通知
    3. 12.3 社区资源
    4. 12.4 商标
    5. 12.5 静电放电警告
    6. 12.6 Glossary
  13. 13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

8.3.3 Input Common-Mode Range

The linear input voltage range of the INA827 input circuitry extends from the negative supply voltage to 1 V below the positive supply, and maintains 88-dB (minimum) common-mode rejection throughout this range. The common-mode range for most common operating conditions is described in Figure 14 and Figure 35 through Figure 38. The INA827 can operate over a wide range of power supplies and VREF configurations, thus making a comprehensive guide to common-mode range limits for all possible conditions impractical to provide.

The most commonly overlooked overload condition occurs when a circuit exceeds the output swing of A1 and A2, which are internal circuit nodes that cannot be measured. Calculating the expected voltages at the output of A1 and A2 (see Figure 57) provides a check for the most common overload conditions. The A1 and A2 designs are identical and the outputs can swing to within approximately 100 mV of the power-supply rails. For example, when the A2 output is saturated, A1 can continue to be in linear operation and responding to changes in the noninverting input voltage. This difference can give the appearance of linear operation but the output voltage is invalid.

A single-supply instrumentation amplifier has special design considerations. To achieve a common-mode range that extends to single-supply ground, the INA827 employs a current-feedback topology with PNP input transistors; see Figure 57. The matched PNP transistors (Q1 and Q2) shift the input voltages of both inputs up by a diode drop and (through the feedback network) shift the output of A1 and A2 by approximately +0.8 V. With both inputs and VREF at single-supply ground (negative power supply), the output of A1 and A2 is well within the linear range, allowing differential measurements to be made at the GND level. As a result of this input level-shifting, the voltages at pins 2 and 3 are not equal to the respective input pin voltages (pins 1 and 4). For most applications, this inequality is not important because only the gain-setting resistor connects to these pins.