SBOS366E August   2006  – January 2021 INA193A-Q1 , INA194A-Q1 , INA195A-Q1 , INA196A-Q1 , INA197A-Q1 , INA198A-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 Basic Connection
      2. 7.3.2 Selecting RS
      3. 7.3.3 Inside the INA19xA
      4. 7.3.4 Power Supply
    4. 7.4 Device Functional Modes
      1. 7.4.1 Input Filtering
      2. 7.4.2 Accuracy Variations as a Result Of VSENSE and Common Mode Voltage
        1. 7.4.2.1 Normal Case 1: VSENSE ≥ 20 mV, VCM ≥ VS
        2. 7.4.2.2 Normal Case 2: VSENSE ≥ 20 mV, VCM < VS
        3. 7.4.2.3 Low VSENSE Case 1: VSENSE < 20 mV, –16 V ≤ VCM < 0; and Low VSENSE Case 3: VSENSE < 20 mV, VS < VCM ≤ 80 V
        4. 7.4.2.4 Low VSENSE Case 2: VSENSE < 20 mV, 0 V ≤ VCM ≤ VS
      3. 7.4.3 Shutdown
      4. 7.4.4 Transient Protection
      5. 7.4.5 Output Voltage Range
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 RFI/EMI
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.1 Input Filtering

An obvious and straightforward location for filtering is at the output of the INA19xA series; however, this location negates the advantage of the low output impedance of the internal buffer. The only other option for filtering is at the input pins of the INA19xA, which is complicated by the internal 5-kΩ ± 30% input impedance (see Figure 7-6). Using the lowest possible resistor values minimizes both the initial shift in gain and effects of tolerance. The effect on initial gain is given by:

Equation 1. GUID-1B0EF5ED-D0FD-4CE5-9CD8-79ADA5D482E5-low.gif

Total effect on gain error can be calculated by replacing the 5-kΩ term with 5 kΩ – 30% (or 3.5 kΩ) or 5 kΩ + 30% (or 6.5 kΩ). The tolerance extremes of RFILT can also be inserted into the equation. If a pair of 100-Ω 1% resistors are used on the inputs, the initial gain error is 1.96%. Worst-case tolerance conditions always occur at the lower excursion of the internal 5-kΩ resistor (3.5 kΩ), and the higher excursion of RFILT, 3% in this case.

The specified accuracy of the INA19xA must then be combined in addition to these tolerances. While this discussion treats accuracy worst-case conditions by combining the extremes of the resistor values, it is appropriate to use geometric mean or root sum square calculations to total the effects of accuracy variations.

GUID-1C4EC440-A3B2-4DF4-BB48-A385521B8133-low.gifFigure 7-6 Input Filter (Gain Error = 1.5% to –2.2%)