SLVSFV5B July   2023  – October 2024 DRV8262

PRODUCTION DATA  

  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
      1. 5.4.1 Transient Thermal Impedance & Current Capability
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1  Overview
    2. 6.2  Functional Block Diagram
    3. 6.3  Feature Description
    4. 6.4  Device Operational Modes
      1. 6.4.1 Dual H-Bridge Mode (MODE1 = 0)
      2. 6.4.2 Single H-Bridge Mode (MODE1 = 1)
    5. 6.5  Current Sensing and Regulation
      1. 6.5.1 Current Sensing and Feedback
      2. 6.5.2 Current Regulation
        1. 6.5.2.1 Mixed Decay
        2. 6.5.2.2 Smart tune Dynamic Decay
      3. 6.5.3 Current Sensing with External Resistor
    6. 6.6  Charge Pump
    7. 6.7  Linear Voltage Regulator
    8. 6.8  VCC Voltage Supply
    9. 6.9  Logic Level, Tri-Level and Quad-Level Pin Diagrams
    10. 6.10 Protection Circuits
      1. 6.10.1 VM Undervoltage Lockout (UVLO)
      2. 6.10.2 VCP Undervoltage Lockout (CPUV)
      3. 6.10.3 Logic Supply Power on Reset (POR)
      4. 6.10.4 Overcurrent Protection (OCP)
      5. 6.10.5 Thermal Shutdown (OTSD)
      6. 6.10.6 nFAULT Output
      7. 6.10.7 Fault Condition Summary
    11. 6.11 Device Functional Modes
      1. 6.11.1 Sleep Mode
      2. 6.11.2 Operating Mode
      3. 6.11.3 nSLEEP Reset Pulse
      4. 6.11.4 Functional Modes Summary
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Driving Brushed-DC Motors
        1. 7.1.1.1 Brushed-DC Motor Driver Typical Application
        2. 7.1.1.2 Power Loss Calculations - Dual H-bridge
        3. 7.1.1.3 Power Loss Calculations - Single H-bridge
        4. 7.1.1.4 Junction Temperature Estimation
        5. 7.1.1.5 Application Performance Plots
      2. 7.1.2 Driving Stepper Motors
        1. 7.1.2.1 Stepper Driver Typical Application
        2. 7.1.2.2 Power Loss Calculations
        3. 7.1.2.3 Junction Temperature Estimation
      3. 7.1.3 Driving Thermoelectric Coolers (TEC)
    2. 7.2 Power Supply Recommendations
      1. 7.2.1 Bulk Capacitance
      2. 7.2.2 Power Supplies
    3. 7.3 Layout
      1. 7.3.1 Layout Guidelines
      2. 7.3.2 Layout Example
  9. 8 Package Thermal Considerations
    1. 8.1 DDW Package
      1. 8.1.1 Thermal Performance
        1. 8.1.1.1 Steady-State Thermal Performance
        2. 8.1.1.2 Transient Thermal Performance
    2. 8.2 DDV Package
    3. 8.3 PCB Material Recommendation
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information

7.1.1.4 Junction Temperature Estimation

For an ambient temperature of TA and total power dissipation (PTOT), the junction temperature (TJ) is calculated as -

TJ = TA + (PTOT x RθJA)

Considering a JEDEC standard 4-layer PCB, the junction-to-ambient thermal resistance (RθJA) is 22.2 °C/W for the DDW package.

Assuming 25°C ambient temperature, the junction temperature is calculated as shown below -

Equation 4. TJ = 25°C + (3.84 W x 22.2 °C/W) = 110.2 °C

For more accurate calculation, consider the dependency of on-resistance of FETs with device junction temperature shown in the Typical Operating Characteristics section.

For example,

  • At 110.2 °C junction temperature, the on-resistance will likely increase by a factor of 1.4 compared to the on-resistance at 25 °C.

  • The initial estimate of conduction loss was 3.2 W.

  • New estimate of conduction loss will therefore be 3.2 W x 1.4 = 4.48 W.

  • New estimate of the total power loss will accordingly be 5.12 W.

  • New estimate of junction temperature for the DDW package will be 138.7 °C.

  • Further iterations are unlikely to increase the junction temperature estimate by significant amount.

When using the DDV package, if a heat sink with less than 4 °C/W thermal resistance is chosen, the junction to ambient thermal resistance can be lower than 5 °C/W. The initial estimate of the junction temperature with the DDV package in this application will therefore be -

Equation 5. TJ = 25°C + (3.84-W x 5 °C/W) = 44.2 °C

The DDV package will be able to deliver up to 10 A RMS current to both brushed-DC motors in dual H-bridge mode and up to 20 A RMS current to a brushed-DC motor in single H-bridge mode.