SLVSI22 August   2025 DRV8844A

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
    5. 5.5 Electrical Characteristics
    6. 5.6 Switching Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Output Stage
      2. 6.3.2 Logic Inputs
      3. 6.3.3 Bridge Control
      4. 6.3.4 Charge Pump
      5. 6.3.5 Protection Circuits
        1. 6.3.5.1 Overcurrent Protection (OCP)
        2. 6.3.5.2 Thermal Shutdown (TSD)
        3. 6.3.5.3 Undervoltage Lockout (UVLO)
      6. 6.3.6 CLR_FAULT and nSLEEP Operation
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Application Information
      1. 7.2.1 Driving Solenoid Loads
      2. 7.2.2 Driving Stepper Motor
      3. 7.2.3 Driving Brushed DC motor
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Bulk Capacitance
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
      3. 7.4.3 Thermal Considerations
        1. 7.4.3.1 Heatsinking
      4. 7.4.4 Power Dissipation
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Community Resources
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.4 Power Dissipation

Power dissipation in the DRV8844A is dominated by the power dissipated in the output FET resistance, or RDS(ON). Average power dissipation of each H-bridge when running a DC motor can be roughly estimated by Equation 5.

Equation 5. DRV8844A

where

  • P is the power dissipation of one H-bridge
  • RDS(ON) is the resistance of each FET
  • IOUT is the RMS output current being applied to each winding

IOUT is equal to the average current drawn by the DC motor. Note that at start-up and fault conditions this current is much higher than normal running current; these peak currents and the duration also need to be taken into consideration. The factor of 2 comes from the fact that at any instant two FETs are conducting winding current (one high-side and one low-side).

The total device dissipation is the power dissipated in each of the two H-bridges added together.

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.