SLVSDA4C January   2017  – March 2020 DRV8886

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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  Current Regulation
      5. 7.3.5  Controlling RREF With an MCU DAC
        1. 7.3.5.1 Various Sources of Error
          1. 7.3.5.1.1 VRREF, ARREF, and RREF Error
          2. 7.3.5.1.2 VDAC Error
        2. 7.3.5.2 Application-Specific Error Calculations
      6. 7.3.6  Decay Modes
        1. 7.3.6.1 Mode 1: Slow Decay for Increasing Current, Mixed Decay for Decreasing Current
        2. 7.3.6.2 Mode 2: Mixed Decay for Increasing and Decreasing Current
        3. 7.3.6.3 Mode 3: Slow Decay for Increasing and Decreasing Current
      7. 7.3.7  Blanking Time
      8. 7.3.8  Charge Pump
      9. 7.3.9  Linear Voltage Regulators
      10. 7.3.10 Logic and Multi-Level Pin Diagrams
      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)
        4. 7.3.11.4 Thermal Shutdown (TSD)
    4. 7.4 Device Functional Modes
  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
  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 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  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 RREF resistor and the TRQ setting. During stepping, IFS defines the current chopping threshold (ITRIP) for the maximum current step.

Equation 7. DRV8886 eq_02_I_FS_lvsd39.gif

NOTE

The IFS current must also follow Equation 8 to avoid saturating the motor. VM is the motor supply voltage, and RL is the motor winding resistance.
Equation 8. DRV8886 eq_03_I_FS_lvsd39.gif