SBOSAD1 May   2024 INA791B

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Integrated Shunt Resistor
      2. 6.3.2 Safe Operating Area
      3. 6.3.3 Short-Circuit Duration
      4. 6.3.4 Temperature Stability
    4. 6.4 Device Functional Modes
      1. 6.4.1 Adjusting the Output With the Reference Pin
        1. 6.4.1.1 Reference Pin Connections for Unidirectional Current Measurements
        2. 6.4.1.2 Ground Referenced Output
        3. 6.4.1.3 Reference Pin Connections for Bidirectional Current Measurements
        4. 6.4.1.4 Output Set to Mid-Supply Voltage
      2. 6.4.2 Adjustable Gain Set Using External Resistors
        1. 6.4.2.1 Adjustable Unity Gain
      3. 6.4.3 Thermal Alert Function
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Calculating Total Error
        1. 7.1.1.1 Error Sources
        2. 7.1.1.2 Reference Voltage Rejection Ratio Error
        3. 7.1.1.3 External Adjustable Gain Error
        4. 7.1.1.4 Total Error Example 1
        5. 7.1.1.5 Total Error Example 2
        6. 7.1.1.6 Total Error Example 3
    2. 7.2 Typical Applications
      1. 7.2.1 High-Side, High-Drive, Solenoid Current-Sense Application
        1. 7.2.1.1 Design Requirements
  9. 8 Power Supply Recommendations
  10. 9 Layout Example
  11. 10Layout Guidelines
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

7.1.1.6 Total Error Example 3

Table 7-3 Total Error Calculation: Example 3(1)
TERMSYMBOLEQUATIONTYPICAL VALUE
Initial input offset with Temp drift IOS_T I O S +   d I o s d T × ∆   T 92.5mA
Added input offset because of common-mode voltage IOS_CM C M R R × | ( V C M – 48 V   ) | 2.8mA
Added input offset because of reference voltage IOS_REF R V R R × | ( V S 2 – V R E F   ) | 31.25mA
Total input offset Current IOS_Total ( I O S _ T ) 2 + ( I O S _ C M ) 2 + ( I O S _ R E F ) 2 97.67mA
Error from input offset ErrorIOS I O S _ T o t a l I S e n s e × 100 0.39%
Gain error with Gain drift ErrorG G E r r o r + G E r r o r _ d r i f t × ∆   T 0.7%
Nonlinearity error ErrorLin — 0.01%
External Gain Resistor Error + Drift ErrorG_R Equation 4 0.6%
Total error — ( E r r o r I O S ) 2 + ( E r r o r G _ R ) 2 +   ( E r r o r G ) 2 + ( E r r o r L i n ) 2 1.01%
(1) The data for Total Error Example 3 was taken with the INA791x, VS = 5V, VCM = 12V, VREF = 0V, T = 125°C, External Gain = 4 (Total Gain = 80mV/A), External Resistor Tolerance = 0.25%, External Resistor Drift = 25ppm/°C and ISENSE = 25A.