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

8.4.4 Start-Up Current Setting

The start-up current setting is to control the peak start-up during open loop. During open loop operation, it is desirable to control the magnitude of drive current applied to the motor. This is helpful in controlling and optimizing the rate of acceleration. The limit takes effect during reverse drive, align, and acceleration.

The start current is set by programming the OpenLCurr[1:0] bits. The current should be selected to allow the motor to reliably accelerate to the handoff threshold. Heavier loads may require a higher current setting, but it should be noted that the rate of acceleration will be limited by the acceleration rate (StAccel[2:0], StAccel2[2:0]). If the motor is started with more current than necessary to reliably reach the handoff threshold, it results in higher power consumption.

The start current is controlled based on the relationship shown in Equation 3 and Figure 19. The duty cycle applied to the motor is derived from the calculated value for ULimit and the magnitude of the supply voltage, VCC, as well as the drive state of the motor.

Equation 3. DRV10975 DRV10975Z eq_U_Limit_LVSCP2.gif

where

  • ILimit is configured by OpenLCurr[1:0]
  • Rm is configured by Rm[6:0]
  • Speed is variable based open-loop acceleration profile of the motor
  • Kt is configured by Kt[6:0]
DRV10975 DRV10975Z current_motor_startup_LVSCP2.gifFigure 19. Motor Start-Up Current