SLOSE55C May   2020  – July 2022 DRV8426

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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 Indexer Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Stepper Motor Driver Current Ratings
        1. 7.3.1.1 Peak Current Rating
        2. 7.3.1.2 RMS Current Rating
        3. 7.3.1.3 Full-Scale Current Rating
      2. 7.3.2  PWM Motor Drivers
      3. 7.3.3  Microstepping Indexer
      4. 7.3.4  Controlling VREF with an MCU DAC
      5. 7.3.5  Current Regulation
      6. 7.3.6  Decay Modes
        1. 7.3.6.1 Slow Decay for Increasing and Decreasing Current
        2. 7.3.6.2 Slow Decay for Increasing Current, Mixed Decay for Decreasing Current
        3. 7.3.6.3 Mixed Decay for Increasing and Decreasing Current
        4. 7.3.6.4 Smart tune Dynamic Decay
        5. 7.3.6.5 Smart tune Ripple Control
        6. 7.3.6.6 PWM OFF Time
        7. 7.3.6.7 Blanking time
      7. 7.3.7  Charge Pump
      8. 7.3.8  Linear Voltage Regulators
      9. 7.3.9  Logic Level, tri-level and quad-level Pin Diagrams
      10. 7.3.10 nFAULT Pin
      11. 7.3.11 Protection Circuits
        1. 7.3.11.1 VM Undervoltage Lockout (UVLO)
        2. 7.3.11.2 VCP Undervoltage Lockout (CPUV)
        3. 7.3.11.3 Overcurrent Protection (OCP)
          1. 7.3.11.3.1 Latched Shutdown
          2. 7.3.11.3.2 Automatic Retry
        4. 7.3.11.4 Thermal Shutdown (OTSD)
          1. 7.3.11.4.1 Latched Shutdown
          2. 7.3.11.4.2 Automatic Retry
        5. 7.3.11.5 Fault Condition Summary
    4. 7.4 Device Functional Modes
      1. 7.4.1 Sleep Mode (nSLEEP = 0)
      2. 7.4.2 Disable Mode (nSLEEP = 1, ENABLE = 0)
      3. 7.4.3 Operating Mode (nSLEEP = 1, ENABLE = Hi-Z/1)
      4. 7.4.4 nSLEEP Reset Pulse
      5. 7.4.5 Functional Modes Summary
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Stepper Motor Speed
        2. 8.2.2.2 Current Regulation
        3. 8.2.2.3 Decay Modes
      3. 8.2.3 Application Curves
      4. 8.2.4 Thermal Application
        1. 8.2.4.1 Power Dissipation
          1. 8.2.4.1.1 Conduction Loss
          2. 8.2.4.1.2 Switching Loss
          3. 8.2.4.1.3 Power Dissipation Due to Quiescent Current
          4. 8.2.4.1.4 Total Power Dissipation
        2. 8.2.4.2 Device Junction Temperature Estimation
  9. 9 Power Supply Recommendations
    1. 9.1 Bulk Capacitance
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.2 Current Regulation

In a stepper motor, the full-scale current (IFS) is the maximum current driven through either winding. This quantity depends on the VREF voltage. The maximum allowable voltage on the VREF pin is 3.3 V for DRV8426. DVDD can be used to provide VREF through a resistor divider. During stepping, IFS defines the current chopping threshold (ITRIP) for the maximum current step. IFS (A) = VREF (V) / 2.2 (V/A)