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

9.2.2.1 Stepper Motor Speed

The first step in configuring the DRV8885 requires the desired motor speed and microstepping level. If the target application requires a constant speed, then a square wave with frequency ƒstep must be applied to the STEP pin.

If the target motor speed is too high, the motor will not spin. Make sure that the motor can support the target speed.

For a desired motor speed (v), microstepping level (nm), and motor full step angle (θstep),

Equation 3. DRV8885 eq_fstep_1_lvsd18.gif

θstep can be found in the stepper motor data sheet, or written on the motor itself.

For the DRV8885, the microstepping level is set by the Mx pins and can be any of the settings in the table below. Higher microstepping will mean a smother motor motion and less audible noise, but will increase switching losses and require a higher fstep to achieve the same motor speed.

Table 11. Microstepping Indexer Settings

M1 M0 STEP MODE
0 0 Full step (2-phase excitation) with 71% current
0 1 1/16 step
1 0 1/2 step
1 1 1/4 step
0 Z 1/8 step
1 Z Non-circular 1/2 step

Example: Target 120 rpm at 1/8 microstep mode. The motor is 1.8°/step

Equation 4. DRV8885 eq_fstep_2_lvsd18.gif