SBOS945B November   2020  – April 2021 INA849

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 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 Adjustable Gain Setting
      2. 8.3.2 Gain Drift
      3. 8.3.3 Wide Input Common-Mode Range
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Reference Pin
      2. 9.1.2 Input Bias Current Return Path
      3. 9.1.3 Thermal Effects due to Power Dissipation
    2. 9.2 Typical Application
      1. 9.2.1 Sensor Conditioning Circuit
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
      2. 9.2.2 Phantom Power in Microphone Preamplifier Circuit
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.1 Overview

The INA849 is a monolithic, precision, instrumentation amplifier that incorporates a current-feedback input stage and a four-resistor difference amplifier output stage. The functional block diagram in the next section shows how the differential input voltage is buffered by Q1 and Q2, and is forced across RG, which causes a signal current to flow through RG, R1, and R2. The output difference amplifier, A3, removes the common-mode component of the input signal and refers the output signal to the REF pin. The VBE and voltage drop across R1 and R2 produce output voltages on A1 and A2 that are approximately 0.8 V lower than the input voltages.