SBOS307G May   2004  – January 2015 INA193 , INA194 , INA195 , INA196 , INA197 , INA198

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 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
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Basic Connection
      2. 8.3.2 Selecting RS
      3. 8.3.3 Inside the INA193-INA198
    4. 8.4 Device Functional Modes
      1. 8.4.1 Input Filtering
      2. 8.4.2 Accuracy Variations as a Result of VSENSE and Common-Mode Voltage
        1. 8.4.2.1 Normal Case 1: VSENSE ≥ 20mv, VCM ≥ VS
        2. 8.4.2.2 Normal Case 2: VSENSE ≥ 20mv, VCM < VS
        3. 8.4.2.3 Low VSENSE Case 1: VSENSE < 20mV, −16v ≤ VCM < 0; and Low VSENSE Case 3: VSENSE < 20mV, VS < VCM ≤ 80V
        4. 8.4.2.4 Low VSENSE Case 2: VSENSE < 20 mV, 0 V ≤ VCM ≤ VS
      3. 8.4.3 Shutdown
      4. 8.4.4 Transient Protection
      5. 8.4.5 Output Voltage Range
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 RFI and EMI
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

9.1 Application Information

The INA193-INA198 devices measure the voltage developed across a current-sensing resistor when current passes through it. The ability to have shunt common-mode voltages from −16-V to +80-V drive and control the output signal with Vs offers multiple configurations, as discussed throughout this section.

9.2 Typical Application

The device is a unidirectional, current-sense amplifier capable of measuring currents through a resistive shunt with shunt common-mode voltages from −16 V to 80 V. Two devices can be configured for bidirectional monitoring and is common in applications that include charging and discharging operations where the current flow-through resistor can change directions.

INA193 INA194 INA195 INA196 INA197 INA198 ai_bidirect_bos307.gif Figure 29. Bi-Directional Current Monitoring

9.2.1 Design Requirements

Vsupply is set to 12 V, Vref at 2.5 V and a 10-mΩ shunt. The accuracy of the current will typically be less than 0.5% for current greater than ±2 A. For current lower than ±2 A, the accuracy will vary; use the Device Functional Modes section for accuracy considerations.

9.2.2 Detailed Design Procedure

The ability to measure this current flowing in both directions is enabled by adding a unity gain amplifier with a VREF, as shown in Figure 29. The output then responds by increasing above VREF for positive differential signals (relative to the IN – pin) and responds by decreasing below VREF for negative differential signals. This reference voltage applied to the REF pin can be set anywhere between 0 V to V+. For bidirectional applications, VREF is typically set at mid- scale for equal signal range in both current directions. In some cases, however, VREF is set at a voltage other than mid-scale when the bidirectional current and corresponding output signal do not need to be symmetrical.

9.2.3 Application Curve

An example output response of a bidirectional configuration is shown in Figure 30. With the REF pin connected to a reference voltage, 2.5 V in this case, the output voltage is biased upwards by this reference level. The output rises above the reference voltage for positive differential input signals and falls below the reference voltage for negative differential input signals.

INA193 INA194 INA195 INA196 INA197 INA198 D999_SBOS307.gif Figure 30. Output Voltage vs Shunt Input Current