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

7.3.5.1.1 VRREF, ARREF, and RREF Error

To observe how VRREF, ARREF, and RREFVRREF affect the IFS error , Equation 3 and Equation 4 are used with the data sheet values from earlier while VDAC voltage remains constant. Table 8, Table 9, and Table 10 list the results at different current levels (1 A, 400 mA, and 200 mA, respectively).

Table 8. Worst Case Calculation—IFS Error at 1 A

Parameter Minimum Typical Maximum
VDAC 0.4107 0.4107 0.4107
ARREF 28100 30000 31900
VRREF 1.18 1.232 1.28
RREF 19800 20000 20200
IFS (mA) 906.95 1000 1094.21
Error (%) –9.30 9.42

Table 9. Worst Case Calculation—IFS Error at 400 mA

Parameter Minimum Typical Maximum
VDAC 0.9035 0.9035 0.9035
ARREF 28100 30000 31900
VRREF 1.18 1.232 1.28
RREF 19800 20000 20200
IFS (mA) 326.00 400 473.93
Error (%) –18.50 18.48

Table 10. Worst Case Calculation—IFS Error at 200 mA

Parameter Minimum Typical Maximum
VDAC 1.0677 1.0677 1.0677
ARREF 28100 30000 31900
VRREF 1.18 1.232 1.28
RREF 19800 20000 20200
IFS (mA) 135.35 200 267.18
Error (%) –33.83 33.59

These tables show that as the IFS current level decreases, the overall error percentage increases due to increasing offset error from the internal signal chain. It is worthy to clarify that the VRREF and ARREF values in these tables are data sheet values which represent the characterization data variation across a wide range of temperatures and voltages with additional margin. For information on how to further minimize this percentage of error based on targeted characterization data for VRREF and ARREF, see Application-Specific Error Calculations.