SBOSAI8A March   2025  – July 2025 INA630

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Setting the Gain
        1. 7.3.1.1 Gain Error and Drift
      2. 7.3.2 Linear Input Voltage Range
      3. 7.3.3 Input Protection
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Reference Pin
      2. 8.1.2 Input Bias Current Return Path
    2. 8.2 Typical Applications
      1. 8.2.1 Current Shunt Monitoring in Battery Testing Systems
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Examples
  10. 9 Device and Documentation Support
    1. 9.1 Third-Party Products Disclaimer
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.1.2 Detailed Design Procedure

This chapter details the procedure to lay out the gain resistor network, containing R1 and R2. Additional guidance is provided to verify that the given input voltage lies within the allowed operating range.

The selection of the current shunt resistor is an important step for an accurate battery test system. A large shunt resistor increases power dissipation which degrades the drift performance. A small resistor on the other side requires a high-performance front end. For this design, the given charging current ICHARGE is ±100A, so RSENSE is selected to be 200μΩ for best trade-off.

In charging mode, Equation 3 show the sense voltage to the input of the INA630:

Equation 3. VSENSE = ICHARGE × RSENSE = ±20mV

The full-scale range for the selected ADC is at 5V. The reference pin is grounded. Equation 4 shows the gain:

Equation 4. G = VOUT / VSENSE = 125V/V
  • G represents the gain of the instrumentation amplifier.
  • VSENSE represents the differential voltage at the INA630 inputs which is within the maximum allowed differential input voltage of ±125mV.

Select R1 as ≥ 1kΩ to optimize accuracy of the circuit. Equation 5 shows the R1:

Equation 5. R2 = R1 × (G­−1) = R2 = 1kΩ × (125−1) = 124kΩ

The maximum common-mode voltage of the application is the same as the maximum voltage on the battery cell which is at 5V. The minimum common-mode voltage is the discharged battery cell which during manufacturing flow can be close to 0V. Due to the architecture the limitations for maximum common-mode voltage are simply given by VIN(min) = (V­­−) +1.75V and VIN(max) = (V+) − 1.5V, in this example VIN(min)= −8.25V and VIN(max) = 8.5V. The operating input voltage is at 5V+20mV (maximum) and 0V–20mV (minimum) which is within the allowed range.