TIDUEX5 October   2020

 

  1.   Description
  2.   Resources
  3.   Applications
  4.   Features
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Ideal Diode Design Overview
      2. 2.2.2 Current Sensing Amplifier Design Overview
      3. 2.2.3 OR Gate Design Overview
      4. 2.2.4 MOSFET Selection
        1. 2.2.4.1 Blocking MOSFET
        2. 2.2.4.2 Hot-Swap MOSFET
      5. 2.2.5 TVS Input Diode Selection
      6. 2.2.6 Inrush Current
    3. 2.3 Highlighted Products
      1. 2.3.1 LM74810-Q1
      2. 2.3.2 INA302-Q1
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 Getting Started
      2. 3.1.2 Testing and Results
        1. 3.1.2.1 Over-Voltage Protection Cut-Off Mode
        2. 3.1.2.2 Over-Voltage Protection Clamping-Mode
        3. 3.1.2.3 ISO7637-2 Pulse 1
        4. 3.1.2.4 Overcurrent Protection
        5. 3.1.2.5 Load Dump
        6. 3.1.2.6 Cold Crank, Warm Start, and Cold Start
          1. 3.1.2.6.1 Cold Crank
          2. 3.1.2.6.2 Warm Start
          3. 3.1.2.6.3 Cold Start
        7. 3.1.2.7 Standby Current
        8. 3.1.2.8 Currency Sense Accuracy
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks

3.1.2.8 Currency Sense Accuracy

Current sense accuracy testing was performed for the design, beginning at low current levels and increasing the current up to 24A max. The shunt resistor value for the design was a 1mohm resistor and the IN302 had a gain of 50V/V. Table 3-1 includes currents measured by INA302 in comparison to the current being drawn by the E-load.

Table 3-1 Current Sensing Accuracy Test Data

ELOAD CURRENT

INA OUT (V)

INA OUT (A) OUT/(Rs*Gain)

0.53

0.02595

0.519

1.03

0.05092

1.0184

2.03

0.10082

2.0164

3.04

0.15157

3.0314

5.04

0.2513

5.026

10.05

0.50196

10.0392

15.03

0.7514

15.028

20.02

1.0016

20.032

24.03

1.202

24.04