SBOS122E December   1999  – December 2017 INA138 , INA168

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 the Shunt Resistor 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
      5. 8.2.5 Bipolar Current Measurement Using Differential Input of 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

1 Features

  • Complete Unipolar High-Side Current Measurement Circuit
  • Wide Supply and Common-Mode Range
  • INA138: 2.7 V to 36 V
  • INA168: 2.7 V to 60 V
  • Independent Supply and Input Common-Mode Voltages
  • Single Resistor Gain Set
  • Low Quiescent Current (25 µA Typical)
  • Wide Temperature Range: –40°C to +125°C
  • 5-Pin SOT-23 Package

2 Applications

  • Current Shunt Measurement:
    • Telephone, Computers
  • Portable and Battery-Backup Systems
  • Battery Chargers
  • Power Management
  • Cell Phones
  • Precision Current Source

3 Description

The INA138 and INA168 (INA1x8) are high-side, unipolar, current shunt monitors. Wide input common-mode voltage range, low quiescent current, and tiny SOT-23 packaging enable use in a variety of applications.

Input common-mode and power-supply voltages are independent and can range from 2.7 V to 36 V for the INA138 and 2.7 V to 60 V for the INA168. Quiescent current is only 25 µA, which permits connecting the power supply to either side of the current measurement shunt with minimal error.

The device converts a differential input voltage to a current output. This current is converted back to a voltage with an external load resistor that sets any gain from 1 to over 100. Although designed for current shunt measurement, the circuit invites creative applications in measurement and level shifting.

Both the INA138 and INA168 are available in SOT23-5 and are specified for the –40°C to 125°C temperature range.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
INA138 SOT-23 (5) 2.90 mm × 1.60 mm
INA168
  1. For all available packages, see the package option addendum at the end of the datasheet.

Typical Application Circuit

INA138 INA168 fiirst_page_sbos122.gif