SLVSAW5D July   2011  – December 2024 DRV8803

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
    1.     Pin Functions
  7. 6 Specification
    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 Timing Requirements
    7. 6.7 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 Output Drivers
      2. 7.3.2 Protection Circuits
        1. 7.3.2.1 Overcurrent Protection (OCP)
        2. 7.3.2.2 Thermal Shutdown (TSD)
        3. 7.3.2.3 Undervoltage Lockout (UVLO)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Parallel Interface Operation
      2. 7.4.2 nENBL and RESET Operation
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Application as Load driver
        1. 8.1.1.1 Design Requirements
        2. 8.1.1.2 Detailed Design Procedure
          1. 8.1.1.2.1 Supply Voltage
          2. 8.1.1.2.2 Load Current
            1. 8.1.1.2.2.1 Peak Current
            2. 8.1.1.2.2.2 Hold Current
            3. 8.1.1.2.2.3 Frequency
        3. 8.1.1.3 Application Curves
      2. 8.1.2 Application as Unipolar Stepper Driver
        1. 8.1.2.1 Design Requirements
        2. 8.1.2.2 Detailed Design Procedure
          1. 8.1.2.2.1 Motor Voltage
          2. 8.1.2.2.2 Drive Current
        3. 8.1.2.3 Application Curves
    2.     Power Supply Recommendations
      1. 8.2.1 Bulk Capacitance
    3. 8.2 Layout
      1. 8.2.1 Layout Guidelines
      2. 8.2.2 Layout Example
      3. 8.2.3 Thermal Consideration
        1. 8.2.3.1 Thermal Protection
        2. 8.2.3.2 Power Dissipation
        3. 8.2.3.3 Heatsinking
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Community Resources
    3. 9.3 Trademarks
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.3.2 Power Dissipation

Power dissipation in the DRV8803 device is dominated by the power dissipated in the output FET resistance, or RDS(on). Average power dissipation of each FET when running a static load can be roughly estimated by Equation 3:

Equation 3. DRV8803

where

  • P is the power dissipation of one FET
  • RDS(ON) is the resistance of each FET
  • IOUT is equal to the average current drawn by the load.

At start-up and fault conditions, this current is much higher than normal running current; consider these peak currents and their duration. When driving more than one load simultaneously, the power in all active output stages must be summed.

The maximum amount of power that can be dissipated in the device is dependent on ambient temperature and heatsinking.

Note that RDS(on) increases with temperature, so as the device heats, the power dissipation increases. This must be taken into consideration when sizing the heatsink.