SGLS185F September   2003  – May 2016 INA139-Q1 , INA169-Q1

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 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 the 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 Related Documentation
    2. 11.2 Related Links
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PW|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7 Detailed Description

7.1 Overview

The INA139-Q1 and INA169-Q1 devices (INA1x9-Q1) are comprised of a high voltage, precision operational amplifier, precision thin film resistors trimmed in production to an absolute tolerance and a low noise output transistor. The INA1x9-Q1 are powered from a single power supply, and the input voltages can exceed the power-supply voltage. The INA1x9-Q1 are ideal for measuring small differential voltages, such as those generated across a shunt resistor in the presence of large, common-mode voltages. The Functional Block Diagram illustrates the functional components within both the INA139-Q1 and INA169-Q1 devices.

7.2 Functional Block Diagram

INA139-Q1 INA169-Q1 SBD_SGLS185.gif

7.3 Feature Description

7.3.1 Output Voltage Range

The output of the INA1x9-Q1 is a current that is converted to a voltage by the load resistor, RL. The output current remains accurate within the compliance voltage range of the output circuitry. The shunt voltage and the input common-mode and power-supply voltages limit the maximum possible output swing. The maximum output voltage (VOUT MAX) compliance is limited by either Equation 1 and Equation 2, whichever is lower:

Equation 1. VOUT MAX = (V+) − 0.7 V − (VIN+ − VIN−)

or

Equation 2. VOUT MAX = VIN− − 0.5 V

7.3.2 Bandwidth

Measurement bandwidth is affected by the value of the load resistor, RL. High gain produced by high values of RL yields a narrower measurement bandwidth (see the Typical Characteristics section). For the widest possible bandwidth, keep the capacitive load on the output to a minimum. Reduction in bandwidth due to capacitive load is shown in the Typical Characteristics.

If bandwidth limiting (filtering) is desired, add a capacitor can be added to the output (see Figure 12). This capacitor does not cause instability.

7.4 Device Functional Modes

For proper operation, the INA1x9-Q1 must operate within the specified limits. Operating either device outside of their specified power supply voltage range, or their specified common-mode range, results in unexpected behavior, and is not recommended. Additionally, operating the output beyond the specified limits, with respect to power supply voltage and input common-mode voltage, also produces unexpected results. See the Electrical Characteristics for the device specifications.