SLVSGI0C September   2022  – June 2024 DRV8411

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    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 Diagrams
  8. 7 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 External Components
    4. 8.4 Feature Description
      1. 8.4.1 Bridge Control
        1. 8.4.1.1 Parallel Bridge Interface
      2. 8.4.2 Current Regulation
      3. 8.4.3 Protection Circuits
        1. 8.4.3.1 Overcurrent Protection (OCP)
        2. 8.4.3.2 Thermal Shutdown (TSD)
        3. 8.4.3.3 Undervoltage Lockout (UVLO)
    5. 8.5 Device Functional Modes
      1. 8.5.1 Active Mode
      2. 8.5.2 Low-Power Sleep Mode
      3. 8.5.3 Fault Mode
    6. 8.6 Pin Diagrams
      1. 8.6.1 Logic-Level Inputs
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Typical Application
        1. 9.1.1.1 Stepper Motor Application
          1. 9.1.1.1.1 Design Requirements
          2. 9.1.1.1.2 Detailed Design Procedure
            1. 9.1.1.1.2.1 Stepper Motor Speed
            2. 9.1.1.1.2.2 Current Regulation
            3. 9.1.1.1.2.3 Stepping Modes
              1. 9.1.1.1.2.3.1 Full-Stepping Operation
              2. 9.1.1.1.2.3.2 Half-Stepping Operation with Fast Decay
              3. 9.1.1.1.2.3.3 Half-Stepping Operation with Slow Decay
          3. 9.1.1.1.3 Application Curves
        2. 9.1.1.2 Dual BDC Motor Application
          1. 9.1.1.2.1 Design Requirements
          2. 9.1.1.2.2 Detailed Design Procedure
            1. 9.1.1.2.2.1 Motor Voltage
            2. 9.1.1.2.2.2 Current Regulation
            3. 9.1.1.2.2.3 Sense Resistor
          3. 9.1.1.2.3 Application Curves
        3. 9.1.1.3 Thermal Considerations
          1. 9.1.1.3.1 Maximum Output Current
          2. 9.1.1.3.2 Power Dissipation
          3. 9.1.1.3.3 Thermal Performance
            1. 9.1.1.3.3.1 Steady-State Thermal Performance
            2. 9.1.1.3.3.2 Transient Thermal Performance
        4. 9.1.1.4 Multi-Sourcing with Standard Motor Driver Pinout
    2. 9.2 Power Supply Recommendations
      1. 9.2.1 Bulk Capacitance
      2. 9.2.2 Power Supply and Logic Sequencing
    3. 9.3 Layout
      1. 9.3.1 Layout Guidelines
      2. 9.3.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Community Resources
    4. 10.4 Trademarks
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

9.2.1 Bulk Capacitance

Having an appropriate local bulk capacitance is an important factor in motor drive system design. It is generally beneficial to have more bulk capacitance, while the disadvantages are increased cost and physical size.

The amount of local capacitance needed depends on a variety of factors, including:

  • The highest current required by the motor system
  • The capacitance and ability to source current
  • The amount of parasitic inductance between the power supply and motor system
  • The acceptable voltage ripple
  • The type of motor used (brushed DC, brushless DC, stepper)
  • The motor braking method

The inductance between the power supply and the motor drive system limits the rate current can change from the power supply. If the local bulk capacitance is too small, the system responds to excessive current demands or dumps from the motor with a change in voltage. When adequate bulk capacitance is used, the motor voltage remains stable and high current can be quickly supplied.

The data sheet generally provides a recommended value, but system-level testing is required to determine the appropriate sized bulk capacitor.

DRV8411 Example Setup of Motor Drive System With External Power SupplyFigure 9-23 Example Setup of Motor Drive System With External Power Supply

The voltage rating for bulk capacitors should be higher than the operating voltage, to provide margin for cases when the motor transfers energy to the supply.