JAJSCX0C October   2015  – November 2018 DRV8885

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      マイクロステッピング電流の波形
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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 Characteristics
  8. 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  PWM Motor Drivers
      3. 8.3.3  Microstepping Indexer
      4. 8.3.4  Current Regulation
      5. 8.3.5  Controlling RREF With an MCU
      6. 8.3.6  Decay Modes
        1. 8.3.6.1 Mode 1: Slow Decay for Increasing and Decreasing Current
        2. 8.3.6.2 Mode 2: Slow Decay for Increasing Current, Mixed Decay for Decreasing Current
        3. 8.3.6.3 Mode 3: Mixed Decay for Increasing and Decreasing Current
      7. 8.3.7  Blanking Time
      8. 8.3.8  Charge Pump
      9. 8.3.9  LDO Voltage Regulator
      10. 8.3.10 Logic and Multi-Level Pin Diagrams
      11. 8.3.11 Protection Circuits
        1. 8.3.11.1 VM Undervoltage Lockout (UVLO)
        2. 8.3.11.2 VCP Undervoltage Lockout (CPUV)
        3. 8.3.11.3 Overcurrent Protection (OCP)
        4. 8.3.11.4 Thermal Shutdown (TSD)
    4. 8.4 Device Functional Modes
  9. 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
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Bulk Capacitance
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 ドキュメントのサポート
      1. 12.1.1 関連資料
    2. 12.2 ドキュメントの更新通知を受け取る方法
    3. 12.3 コミュニティ・リソース
    4. 12.4 商標
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13メカニカル、パッケージ、および注文情報

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

8.3.6.3 Mode 3: Mixed Decay for Increasing and Decreasing Current

DRV8885 mode_3_lvsd39.gifFigure 20. Mixed/Mixed Decay Mode

Mixed decay begins as fast decay for a time, followed by slow decay for the remainder of tOFF. In this mode, mixed decay occurs for both increasing and decreasing current steps.

This mode exhibits ripple larger than slow decay, but smaller than fast decay. On decreasing current steps, mixed decay will settle to the new ITRIP level faster than slow decay.

In cases where current is held for a long time (no input in the STEP pin) or at very low stepping speeds, slow decay may not properly regulate current because no back-EMF is present across the motor windings. In this state, motor current can rise very quickly, and requires an excessively large off-time. Increasing/decreasing mixed decay mode allows the current level to stay in regulation when no back-EMF is present across the motor windings.