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

8.3.3 Motor Speed Control

The DRV10975 offers four methods for indirectly controlling the speed of the motor by adjusting the output voltage amplitude. This can be accomplished by varying the supply voltage (VCC) or by controlling the Speed Command. The Speed Command can be controlled in one of three ways. The user can set the Speed Command on the SPEED pin by adjusting either the PWM input (SPEED pin configured for PWM mode) or the analog input (SPEED pin configured for analog mode), or by writing the Speed Command directly through the I2C serial port to SpdCtrl[8:0]. The Speed Command is used to determine the PWM duty cycle output (PWM_DCO) (see Figure 4).

The Speed Command may not always be equal to the PWM_DCO because DRV10975 has implemented the AVS function (see AVS Function), the acceleration current limit function (see Acceleration Current Limit), and the closed loop accelerate function (see Closed Loop Accelerate) to optimize the control performance. These functions can limit the PWM_DCO, which affects the output amplitude.

DRV10975 DRV10975Z MUX_spd_cmd_motor_LVSCP6.gifFigure 4. Multiplexing the Speed Command to the Output Amplitude Applied to the Motor

The output voltage amplitude applied to the motor is accomplished through sine wave modulation so that the phase-to-phase voltage is sinusoidal.

When any phase is measured with respect to ground, the waveform is sinusoidally coupled with third-order harmonics. This encoding technique permits one phase to be held at ground while the other two phases are pulse-width modulated. Figure 5 and Figure 6 show the sinusoidal encoding technique used in the DRV10975.

DRV10975 DRV10975Z PWM_output_avg_LVSCP2.gifFigure 5. PWM Output and the Average Value
DRV10975 DRV10975Z sinusoidal_waves_3rd_LVSCP2.gif
Sinusoidal voltage from phase to phase Sinusoidal voltage with third order harmonics from phase to GND
Figure 6. Representing Sinusoidal Voltages With Third-Order Harmonic Output

The output amplitude is determined by the magnitude of VCC and the PWM duty cycle output (PWM_DCO). The PWM_DCO represents the peak duty cycle that is applied in one electrical cycle. The maximum amplitude is reached when PWM_DCO is at 100%. The peak output amplitude is VCC. When the PWM_DCO is at 50%, the peak amplitude is VCC / 2 (see Figure 7).

DRV10975 DRV10975Z output_V_amp_LVSCP2.gifFigure 7. Output Voltage Amplitude Adjustment