JAJSM96 may   2023 DRV8849

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Revision History
  6. 5 Device Comparison
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Indexer Timing Requirements
    7. 7.7 Typical Operating Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Stepper Motor Driver Current Ratings
        1. 8.3.1.1 Peak Current Rating
        2. 8.3.1.2 RMS Current Rating
        3. 8.3.1.3 Full-Scale Current Rating
      2. 8.3.2 Microstepping Indexer
      3. 8.3.3 Controlling VREF with an MCU DAC
      4. 8.3.4 Current Regulation and Decay Modes
        1. 8.3.4.1 Smart tune Ripple Control
        2. 8.3.4.2 Smart tune Dynamic Decay
        3. 8.3.4.3 Blanking time
      5. 8.3.5 Charge Pump
      6. 8.3.6 Logic Level, tri-level and quad-level Pin Diagrams
      7. 8.3.7 nFAULT Pins
      8. 8.3.8 Protection Circuits
        1. 8.3.8.1 VM Undervoltage Lockout (UVLO)
        2. 8.3.8.2 VCP Undervoltage Lockout (CPUV)
        3. 8.3.8.3 Overcurrent Protection (OCP)
          1. 8.3.8.3.1 Latched Shutdown
          2. 8.3.8.3.2 Automatic Retry
        4. 8.3.8.4 Thermal Shutdown (OTSD)
          1. 8.3.8.4.1 Latched Shutdown
          2. 8.3.8.4.2 Automatic Retry
        5. 8.3.8.5 Fault Condition Summary
    4. 8.4 Device Functional Modes
      1. 8.4.1 Sleep Mode (nSLEEP = 0)
      2. 8.4.2 Disable Mode (nSLEEP = 1, ENABLE = 0)
      3. 8.4.3 Operating Mode (nSLEEP = 1, ENABLE = Hi-Z/1)
      4. 8.4.4 nSLEEP Reset Pulse
      5. 8.4.5 Functional Modes Summary
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Stepper Motor Speed
        2. 9.2.2.2 Current Regulation
        3. 9.2.2.3 Decay Modes
        4. 9.2.2.4 Application Curves
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Bulk Capacitance
  12. 11デバイスおよびドキュメントのサポート
    1. 11.1 関連資料
  13. 12Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

8.3.4.2 Smart tune Dynamic Decay

GUID-E1F216D3-784D-4456-B388-41ACA1F5EB69-low.gifFigure 8-8 Smart tune Dynamic Decay Mode

Unlike smart tune Ripple Control, smart tune Dynamic Decay operates with fixed OFF time. Smart tune Dynamic Decay dynamically adjusts the fast decay percentage of the total mixed decay time. This eliminates the need for motor decay tuning by automatically determining the best mixed decay setting that results in the lowest ripple and best performance for the motor.

The fast decay percentage is optimized iteratively each PWM cycle. If the motor current overshoots the target ITRIP level, then the mixed decay mode becomes more aggressive (by increasing fast decay percentage) on the next cycle to prevent loss of current regulation. If a long drive time must occur to reach the target ITRIP level, the decay mode becomes less aggressive (by reducing fast decay percentage) on the next cycle to operate with less ripple. On falling steps, smart tune Dynamic Decay automatically switches to fast decay to reach the next step quickly. Smart tune Dynamic Decay operates with fixed 8 μs, 16 μs or 32 μs OFF time.

Smart tune Dynamic Decay is optimal for applications that require minimal current ripple but want to maintain a fixed frequency in the current regulation scheme.