JAJSU39 April   2024 DRV8235

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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 I2C Timing Requirements
    7. 6.7 Timing Diagrams
    8. 6.8 Typical Operating Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 External Components
      2. 7.3.2 Summary of Features
      3. 7.3.3 Bridge Control
      4. 7.3.4 Current Sense and Regulation (IPROPI)
        1. 7.3.4.1 Current Sensing
        2. 7.3.4.2 Current Regulation
          1. 7.3.4.2.1 Fixed Off-Time Current Regulation
          2. 7.3.4.2.2 Cycle-By-Cycle Current Regulation
      5. 7.3.5 Stall Detection
      6. 7.3.6 Motor Voltage and Speed Regulation
        1. 7.3.6.1 Internal Bridge Control
        2. 7.3.6.2 Setting Speed/Voltage Regulation Parameters
          1. 7.3.6.2.1 Speed and Voltage Set
          2. 7.3.6.2.2 Speed Scaling Factor
            1. 7.3.6.2.2.1 Target Speed Setting Example
          3. 7.3.6.2.3 Motor Resistance Inverse
          4. 7.3.6.2.4 Motor Resistance Inverse Scale
          5. 7.3.6.2.5 KMC Scaling Factor
          6. 7.3.6.2.6 KMC
          7. 7.3.6.2.7 VSNS_SEL
        3. 7.3.6.3 Soft-Start and Soft-Stop
          1. 7.3.6.3.1 TINRUSH
      7. 7.3.7 Protection Circuits
        1. 7.3.7.1 Overcurrent Protection (OCP)
        2. 7.3.7.2 Thermal Shutdown (TSD)
        3. 7.3.7.3 VM Undervoltage Lockout (VM UVLO)
        4. 7.3.7.4 Overvoltage Protection (OVP)
        5. 7.3.7.5 nFAULT Output
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Low-Power Sleep Mode
      3. 7.4.3 Fault Mode
    5. 7.5 Programming
      1. 7.5.1 I2C Communication
        1. 7.5.1.1 I2C Write
        2. 7.5.1.2 I2C Read
  9. 8 Register Map
    1. 8.1 DRV8235_STATUS Registers
    2. 8.2 DRV8235_CONFIG Registers
    3. 8.3 DRV8235_CTRL Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application: Brushed DC Motor
      1. 9.2.1 Design Requirements
      2. 9.2.2 Stall Detection
        1. 9.2.2.1 Application Description
          1. 9.2.2.1.1 Stall Detection Timing
          2. 9.2.2.1.2 Hardware Stall Threshold Selection
      3. 9.2.3 Motor Speed and Voltage Regulation Application
        1. 9.2.3.1 Tuning Parameters
          1. 9.2.3.1.1 Resistance Parameters
          2. 9.2.3.1.2 KMC and KMC_SCALE
            1. 9.2.3.1.2.1 Case I
            2. 9.2.3.1.2.2 Case II
              1. 9.2.3.1.2.2.1 Method 1: Tuning from Scratch
                1. 9.2.3.1.2.2.1.1 Tuning KMC_SCALE
                2. 9.2.3.1.2.2.1.2 Tuning KMC
              2. 9.2.3.1.2.2.2 Method 2: Using the Proportionality factor
                1. 9.2.3.1.2.2.2.1 Working Example
      4. 9.2.4 Motor Voltage
      5. 9.2.5 Motor Current
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Bulk Capacitance
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
  11. 10デバイスおよびドキュメントのサポート
    1. 10.1 ドキュメントの更新通知を受け取る方法
    2. 10.2 サポート・リソース
    3. 10.3 Trademarks
    4. 10.4 静電気放電に関する注意事項
    5. 10.5 用語集
  12. 11Revision History
  13. 12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
9.2.3.1.2.2.1.1 Tuning KMC_SCALE
  1. Obtain the value of actual ripple speed in rad/s using either of the two methods:
    1. Use an oscilloscope to observe motor current waveform to measure the ripple frequency. This can be done in two ways:
      • Through the IPROPI pin which provides an output proportional to the motor current.
      • Through a current probe.
      The frequency of ripples is observed in Hz on the oscilloscope. Please consider at least 20 ripples while calculating frequency. Divide the number of ripples by the time taken for calculating the frequency in Hz. Convert into rad/s using Equation 12. Please note that this is the recommended method.
    2. Use a tachometer to obtain the motor speed in rpm. Convert the motor speed into ripple speed using Equation 11. Finally, convert the ripple speed in rpm to ripple speed in rad/s using Equation 13.
    Equation 11. Ripple Speed=Motor Speed×NR
    Equation 12. Ripple Speed (in rad/s)=Ripple Speed (in Hz)×2π
    Equation 13. Ripple Speed (in rad/s)=Ripple Speed (in rpm)×2π60
    Where NR is the number of ripples per revolution. Let this value be called OBS_SPEED.
  2. Select the lowest value of KMC_SCALE, 00b. Set KMC to the highest possible value, 255.
  3. Refer to Table 7-13 to set W_SCALE to a value where maximum ripple speed is more than OBS_SPEED. For example, if OBS_SPEED is 6000 rad/s, set W_SCALE to 01b allowing a maximum speed of 8160 rad/s.
  4. Convert the ripple speed on the SPEED register into rad/s by multiplying SPEED with W_SCALE. For example, if SPEED reads 0x04 and W_SCALE is set to 10b (corresponds to 64 rad/s), then ripple speed in rad/s = 4*64 = 256 rad/s. Let this value be called EST_SPEED.
  5. If EST_SPEED is lower than OBS_SPEED, increase KMC_SCALE by one bit.
  6. Repeat steps 4-5 until EST_SPEED is higher than OBS_SPEED.
  7. Set KMC_SCALE to the previous value. For example, if 11b was obtained in the previous step, set KMC_SCALE to 10b. This is the tuned value of KMC_SCALE.
GUID-20240323-SS0I-RBLH-86KQ-FPJPXSWC4MS5-low.svg Figure 9-3 KMC_SCALE Tuning Procedure