SBOS145B August   1993  – December 2025 INA105

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 Recommended Operating Conditions
    3. 5.3 Thermal Information
    4. 5.4 Electrical Characteristics
    5. 5.5 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Gain Error and Drift
      2. 6.3.2 Input Voltage Range
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
    3. 7.3 Additional Applications
      1. 7.3.1 Operational Amplifier Circuits
      2. 7.3.2 Instrumentation Amplifier Circuits
      3. 7.3.3 Voltage Reference Circuits
      4. 7.3.4 Special Function Circuits
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Examples
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Device Nomenclature
      2. 8.1.2 Development Support
        1. 8.1.2.1 PSpice® for TI
        2. 8.1.2.2 TINA-TI (Free Software Download)
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.1 Application Information

Figure 7-1 shows the basic connections required for operation of the INA105. Connect power-supply bypass capacitors close to the device pins.

The differential input signal is connected to pins 2 and 3, as shown. The source impedances connected to the inputs must be nearly equal for good common-mode rejection. A 5Ω mismatch in source impedance can degrade the common-mode rejection of a typical device to approximately 80dB. If the source has a known mismatch in source impedance, an additional resistor in series with one input can be used to preserve good common-mode rejection.

INA105 Basic Power-Supply and Signal Connections Figure 7-1 Basic Power-Supply and Signal Connections

The output is referred to the output reference terminal (pin 1) which is normally grounded. A voltage applied to the Ref terminal is summed with the output signal. This can be used to null offset voltage as shown in Figure 7-2. To maintain good common-mode rejection, keep the source impedance of a signal applied to the Ref terminal less than 10Ω.

Do not interchange pins 1 and 3 or pins 2 and 5, even though nominal resistor values are equal. These resistors are laser trimmed for precise resistor ratios to achieve accurate gain and highest CMR.

INA105 Offset Adjustment Figure 7-2 Offset Adjustment