SBOSAA0C november   2021  – may 2023 INA350

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 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
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Gain-Setting
        1. 8.3.1.1 Gain Error and Drift
      2. 8.3.2 Input Common-Mode Voltage Range
      3. 8.3.3 EMI Rejection
      4. 8.3.4 Typical Specifications and Distributions
      5. 8.3.5 Electrical Overstress
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Reference Pin
      2. 9.1.2 Input Bias Current Return Path
    2. 9.2 Typical Applications
      1. 9.2.1 Resistive-Bridge Pressure Sensor
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 PSpice® for TI
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

9.1.1 Reference Pin

The output voltage of the INA350 is developed with respect to the voltage on the reference pin (REF). Often in dual-supply operation, REF pin connects to the low-impedance system ground. In single-supply operation, offsetting the output signal to a precise mid-supply level is useful (for example, 2.75-V in a 5.5-V supply environment). To accomplish this level shift, a voltage source must be connected to the REF pin to level-shift the output so that the INA350 can drive a single-supply ADC.

The voltage source applied to the reference pin must have a low output impedance. Any resistance at the reference pin (RREF) in is in series with the internal 60-kΩ resistor.

The parasitic resistance at the reference pin (RREF) creates an imbalance in the four resistors of the internal difference amplifier that results in a degraded common-mode rejection ratio (CMRR). For the best performance, keep the source impedance to the REF pin (RREF) less than 5 Ω.

Voltage reference devices are an excellent option for providing a low-impedance voltage source for the reference pin. However, if a resistor voltage divider generates a reference voltage, buffer the divider by an op amp, as shown in Figure 9-1, to avoid CMRR degradation.

GUID-20211020-SS0I-7JQV-G2XZ-BCZMHQHWG9C2-low.svg Figure 9-1 Use an Op Amp to Buffer Reference Voltages