SGLS174J September   2003  – August 2018 INA138-Q1 , INA168-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Circuit
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Output Voltage Range
      2. 7.3.2 Bandwidth
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Operation
    2. 8.2 Typical Applications
      1. 8.2.1 Buffering Output to Drive an ADC
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Selecting RS and RL
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Output Filter
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
      3. 8.2.3 Offsetting the Output Voltage
      4. 8.2.4 Bipolar Current Measurement
        1. 8.2.4.1 Application Curve
      5. 8.2.5 Bipolar Current Measurement Using Differential Input of an ADC
      6. 8.2.6 Multiplexed Measurement Using Logic Signal for Power
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Related Links
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.3 Offsetting the Output Voltage

For many applications using only a single power supply, the output voltage may have to be level shifted away from ground when there is no load current flowing in the shunt resistor. Level shifting the output of the INA1x8-Q1 is easily accomplished by one of two simple methods shown in Figure 14. Method (a) on the left-hand side of Figure 14 shows a simple voltage-divider method. This method is useful for applications that require the output of the INA1x8-Q1 to remain centered with respect to the power supply at zero load current through the shunt resistor. Using this method, the gain is determined by the parallel combination of R1 and R2, while the output offset is determined by the voltage divider ratio of R1 and R2, as shown in Figure 14(a). For applications that require a fixed value of output offset independent of the power-supply voltage, use current-source method (b) shown on the right-hand side of Figure 14. With this method, a REF200 constant current source is used to generate a constant output offset. Using this method, the gain is determined by RL, and the offset is determined by the product of the value of the current source and RL.

INA138-Q1 INA168-Q1 offsetoutvolt_gls174.gifFigure 14. Offsetting the Output Voltage