SBOS035C December   1995  – January 2026 INA2128

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Pin Configuration and Functions
  6. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6Application and Implementation
    1. 6.1 Application Information
    2. 6.2 Typical Application
      1. 6.2.1 Setting The Gain
      2. 6.2.2 Dynamic Performance
      3. 6.2.3 Noise Performance
      4. 6.2.4 Offset Trimming
      5. 6.2.5 Input Bias Current Return Path
      6. 6.2.6 Input Common-Mode Range
      7. 6.2.7 Low-Voltage Operation
      8. 6.2.8 Input Protection
      9. 6.2.9 Channel Crosstalk
  8. 7Device and Documentation Support
    1. 7.1 Device Nomenclature
    2. 7.2 Receiving Notification of Documentation Updates
    3. 7.3 Support Resources
    4. 7.4 Trademarks
    5. 7.5 Electrostatic Discharge Caution
    6. 7.6 Glossary
  9. 8Revision History
  10. 9Mechanical, Packaging, and Orderable Information

6.2.1 Setting The Gain

Gain of the INA2128 is set by connecting a single external resistor, RG, connected as shown:

Equation 1. INA2128

Commonly-used gains and resistor values are shown in Figure 6-1.

The 50kΩ term in Equation 1 comes from the sum of the two internal feedback resistors, A1 and A2. These on-chip metal film resistors are laser-trimmed to accurate absolute values. The accuracy and temperature coefficient of these resistors are included in the gain accuracy and drift specifications of the INA2128.

The stability and temperature drift of the external gain setting resistor, RG, also affects gain. The contribution of RG to gain accuracy and drift can be directly inferred from the gain equation (1). Low resistor values required for high gain can make wiring resistance important. Sockets add to the wiring resistance which contributes additional gain error in gains of approximately 100 or greater.