SLUSEE5E January   2022  – April 2026 TPS4811-Q1

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 Recommended Operating Conditions
    3. 6.3 ESD Ratings
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Charge Pump and Gate Driver output (VS, PU, PD, BST, SRC)
      2. 8.3.2 Capacitive Load Driving
        1. 8.3.2.1 FET Gate Slew Rate Control
        2. 8.3.2.2 Using Precharge FET - (with TPS48111Q1 Only)
      3. 8.3.3 Overcurrent and Short-Circuit Protection
        1. 8.3.3.1 Overcurrent Protection With Auto-Retry
        2. 8.3.3.2 Overcurrent Protection With Latch-Off
        3. 8.3.3.3 Short-Circuit Protection
      4. 8.3.4 Analog Current Monitor Output (IMON)
      5. 8.3.5 Overvoltage (OV) and Undervoltage Protection (UVLO)
      6. 8.3.6 Remote Temperature sensing and Protection (DIODE)
      7. 8.3.7 Output Reverse Polarity Protection
      8. 8.3.8 TPS4811x-Q1 as a Simple Gate Driver
    4. 8.4 Device Functional Mode (Shutdown Mode)
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application: Driving HVAC PTC Heater Load on KL40 Line in Power Distribution Unit
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Selection of Current Sense Resistor, RSNS
        2. 9.2.2.2 Selection of Scaling Resistor, RSET
        3. 9.2.2.3 Programming the Overcurrent Protection Threshold - RIWRN Selection
        4. 9.2.2.4 Programming the Short-Circuit Protection Threshold - RISCP Selection
        5. 9.2.2.5 Programming the Fault Timer Period - CTMR Selection
        6. 9.2.2.6 Selection of MOSFET, Q1
        7. 9.2.2.7 Selection of Bootstrap Capacitor, CBST
        8. 9.2.2.8 Setting the Undervoltage Lockout and Overvoltage Set Point
        9. 9.2.2.9 Choosing the Current Monitoring Resistor, RIMON
      3. 9.2.3 Application Curves
    3. 9.3 Typical Application: Driving B2B FETs With Pre-Charging the Output Capacitance
      1. 9.3.1 Design Requirements
      2. 9.3.2 External Component Selection
        1. 9.3.2.1 Selection of Pre-Charge Resistor
      3. 9.3.3 Application Curves
    4. 9.4 Typical Application: Designing for EMI
      1. 9.4.1 Common EMI Components
      2. 9.4.2 Programming the Overcurrent Protection Threshold with Added DC Resistance - RIWRN
      3. 9.4.3 Choosing the Current Monitoring Resistor with Added DC Resistance - RIMON
      4. 9.4.4 Programming the Short Circuit Protection Threshold with Added DC Resistance - RISCP
    5. 9.5 Power Supply and EMI Recommendations
    6. 9.6 Layout
      1. 9.6.1 Layout Guidelines
      2. 9.6.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

9.2.2.1 Selection of Current Sense Resistor, RSNS

The recommended range of the overcurrent protection threshold voltage, V(SNS_WRN), extends from 10mV to 200mV. Values near the low threshold of 10mV can be affected by the system noise. Values near the upper threshold of 200mV can cause high power dissipation in the current sense resistor. To minimize both the concerns, 25mV is selected as the overcurrent protection threshold voltage. The current sense resistor, RSNS can be calculated using Equation 15.

Equation 15. R S N S = V S N S - W R N I O C = 25 m V 15 A = 1.66 m Ω

The next smaller available sense resistor 1.5mΩ, 1% is chosen.