SBOS946 September   2020 INA848

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 Topology
      2. 8.3.2 Input Common-Mode Range
      3. 8.3.3 Input Protection
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Filter Pin
        1. 9.1.1.1 RC Filter Network
        2. 9.1.1.2 RLC Filter Network
      2. 9.1.2 Input Bias Current Return Path
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Reference Pin
        2. 9.2.2.2 Noise Analysis
          1. 9.2.2.2.1 Reference Voltage Noise Contribution
      3. 9.2.3 Application Curves
  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 INA848 is a monolithic precision instrumentation amplifier incorporating a current-feedback input stage and a four-resistor difference amplifier output stage. 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.

In common instrumentation amplifiers, an external gain resistor is used to set the gain. However, this external gain resistor affects the gain drift due to the mismatch in tempertature coefficient between the external and internal resistors. The INA848 integrates the gain setting resistor with a fixed gain of 2000, thus matching the temperature drifts of the resistor network. This integration results in an total gain accuracy of 5 ppm/°C (maximum).