SLVSCP2F January   2015  – June 2020 DRV10975

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Application Schematic
  4. 4 Revision History
  5. 5 Description (continued)
  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 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 Regulators
        1. 8.3.1.1 Step-Down Regulator
        2. 8.3.1.2 3.3-V and 1.8-V LDO
      2. 8.3.2 Protection Circuits
        1. 8.3.2.1 Thermal Shutdown
        2. 8.3.2.2 Undervoltage Lockout (UVLO)
        3. 8.3.2.3 Overcurrent Protection (OCP)
        4. 8.3.2.4 Lock
      3. 8.3.3 Motor Speed Control
      4. 8.3.4 Sleep or Standby Condition
      5. 8.3.5 Non-Volatile Memory
    4. 8.4 Device Functional Modes
      1. 8.4.1  Motor Parameters
        1. 8.4.1.1 Motor Phase Resistance
        2. 8.4.1.2 BEMF Constant
      2. 8.4.2  Starting the Motor Under Different Initial Conditions
        1. 8.4.2.1 Case 1 – Motor Is Stationary
        2. 8.4.2.2 Case 2 – Motor Is Spinning in the Forward Direction
        3. 8.4.2.3 Case 3 – Motor Is Spinning in the Reverse Direction
      3. 8.4.3  Motor Start Sequence
        1. 8.4.3.1 ISD
        2. 8.4.3.2 Motor Resynchronization
        3. 8.4.3.3 Reverse Drive
        4. 8.4.3.4 Motor Brake
        5. 8.4.3.5 Motor Initialization
          1. 8.4.3.5.1 Align
          2. 8.4.3.5.2 Initial Position Detect (IPD)
            1. 8.4.3.5.2.1 IPD Operation
            2. 8.4.3.5.2.2 IPD Release Mode
            3. 8.4.3.5.2.3 IPD Advance Angle
          3. 8.4.3.5.3 Motor Start
        6. 8.4.3.6 Start-Up Timing
      4. 8.4.4  Start-Up Current Setting
        1. 8.4.4.1 Start-Up Current Ramp-Up
      5. 8.4.5  Closed Loop
        1. 8.4.5.1 Half Cycle Control and Full Cycle Control
        2. 8.4.5.2 Analog Mode Speed Control
        3. 8.4.5.3 Digital PWM Input Mode Speed Control
        4. 8.4.5.4 I2C Mode Speed Control
        5. 8.4.5.5 Closed Loop Accelerate
        6. 8.4.5.6 Control Coefficient
        7. 8.4.5.7 Commutation Control Advance Angle
      6. 8.4.6  Current Limit
        1. 8.4.6.1 Acceleration Current Limit
      7. 8.4.7  Lock Detect and Fault Handling
        1. 8.4.7.1 Lock0: Lock Detection Current Limit Triggered
        2. 8.4.7.2 Lock1: Abnormal Speed
        3. 8.4.7.3 Lock2: Abnormal Kt
        4. 8.4.7.4 Lock3 (Fault3): No Motor Fault
        5. 8.4.7.5 Lock4: Open Loop Motor Stuck Lock
        6. 8.4.7.6 Lock5: Closed Loop Motor Stuck Lock
      8. 8.4.8  AVS Function
        1. 8.4.8.1 Mechanical AVS Function
      9. 8.4.9  PWM Output
      10. 8.4.10 FG Customized Configuration
        1. 8.4.10.1 FG Output Frequency
        2. 8.4.10.2 FG Open-Loop and Lock Behavior
      11. 8.4.11 Diagnostics and Visibility
        1. 8.4.11.1 Motor Status Readback
        2. 8.4.11.2 Motor Speed Readback
          1. 8.4.11.2.1 Two-Byte Register Readback
        3. 8.4.11.3 Motor Electrical Period Readback
        4. 8.4.11.4 BEMF Constant Readback
        5. 8.4.11.5 Motor Estimated Position by IPD
        6. 8.4.11.6 Supply Voltage Readback
        7. 8.4.11.7 Speed Command Readback
        8. 8.4.11.8 Speed Command Buffer Readback
        9. 8.4.11.9 Fault Diagnostics
    5. 8.5 Register Maps
      1. 8.5.1 I2C Serial Interface
      2. 8.5.2 Register Map
      3. 8.5.3 Register Definition
        1. Table 9. Register Description
  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
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Receiving Notification of Documentation Updates
    6. 12.6 Community Resources
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.4.11.2 Motor Speed Readback

The motor operation speed is automatically updated in register MotorSpeed1 and MotorSpeed2 while the motor is spinning. MotorSpeed1 contains the 8 most significant bits and MotorSpeed2 contains the 8 least significant bits. The value is determined by the period for calculated BEMF zero crossings on phase U. The electrical speed of the motor is denoted as Velocity (Hz) and is calculated as shown in Equation 8.

Equation 8. Velocity (Hz) = {MotorSpeed1:MotorSpeed2} / 10

As an example consider the following:

MotorSpeed1 = 0x01;

MotorSpeed2 = 0xFF;

Velocity = 512 (0x01FF) / 10 = 51 Hz

For a 4-pole motor, this translates to: DRV10975 DRV10975Z eq_motor_spd_LVSCP2.gif

The electrical speed of the motor (Hz) readback from MotorSpeed1 and MotorSpeed2 is not accurate and has up to 6% error. For accurate results, it is recommended to read the Motor electrical period (see Motor Electrical Period Readback) and then calculate the electrical speed of the motor (Hz) manually by calculating the inverse of Motor electrical period or measure the frequency of the FG signal output (see FG Output Frequency).