SLLU335A August   2021  – January 2022 MCF8316A

 

  1. 1Revision History
    1.     Trademarks
  2. 2Introduction
    1. 2.1 Hardware and GUI Setup
      1. 2.1.1 Jumper Configuration
      2. 2.1.2 External Connections
      3. 2.1.3 Connecting to the GUI
        1. 2.1.3.1 Connect to computer
        2. 2.1.3.2 Connect to the GUI
        3. 2.1.3.3 Verify Hardware Connection
  3. 3Essential Controls
    1. 3.1 Recommended Default Values
    2. 3.2 Device and Pin Configuration
      1. 3.2.1 Speed Input Mode
    3. 3.3 Control Configuration - Motor Parameters
      1. 3.3.1 Maximum Motor Electrical Speed (Hz)
    4. 3.4 Control configuration - Closed Loop
      1. 3.4.1 Current Limit for Torque PI Loop
    5. 3.5 Testing for Successful Startup into Closed Loop
    6. 3.6 Fault Handling
      1. 3.6.1 MPET IPD Fault [MPET_IPD_Fault]
      2. 3.6.2 MPET BEMF Fault [MPET_BEMF_Fault]
      3. 3.6.3 Abnormal BEMF Fault [ABN_BEMF]
      4. 3.6.4 Lock Current Limit [LOCK_LIMIT]
      5. 3.6.5 Hardware lock Current Limit [HW_LOCK_LIMIT]
      6. 3.6.6 No Motor Fault [NO_MTR]
  4. 4Basic Controls
    1. 4.1 Device and Pin Configuration
      1. 4.1.1 Power Saver or Sleep Mode for Battery Operated Applications
      2. 4.1.2 Direction and Brake Pin Override
    2. 4.2 System Level Configuration
      1. 4.2.1 Tracking Motor Speed Feedback in Real Time
      2. 4.2.2 Improving Acoustic Performance
      3. 4.2.3 Protecting the Power supply
      4. 4.2.4 Monitoring Power Supply Voltage Fluctuations for Normal Motor Operation
    3. 4.3 Control Configurations
      1. 4.3.1  Motor Parameter Estimation to Minimize Motor Parameter Variation Effects
      2. 4.3.2  Initial Speed Detection of the Motor for Reliable Motor Resynchronization
      3. 4.3.3  Unidirectional Motor Drive Detecting Backward Spin
      4. 4.3.4  Preventing Back Spin of Rotor During Startup
      5. 4.3.5  Faster Startup Timing
      6. 4.3.6  Gradual and Smooth Start up Motion
      7. 4.3.7  Improving Speed Regulation
      8. 4.3.8  Stopping Motor Quickly
      9. 4.3.9  Preventing Supply Voltage Overshoot During Motor Stop.
      10. 4.3.10 Protecting Against Rotor Lock or Stall Condition
      11. 4.3.11 Maximizing Thermal Efficiency and Increasing Thermal Performance
      12. 4.3.12 Mitigating Electromagnetic Interference (EMI)
      13. 4.3.13 Faster deceleration

4.3.2 Initial Speed Detection of the Motor for Reliable Motor Resynchronization

The Initial Speed Detection (ISD) function is used to identify the initial condition of the motor. It is important to know the initial condition of the motor for reliable resynchronization. Motor resynchronization failures can occur when the device attempts to start the motor while the motor is coasting or spinning in the direction opposite to the intended direction of spin. Motors can coast in applications that require frequent motor starts and stops, or if the motor Is being forced externally or if there is a power interruption. Motors can spin in the direction opposite to the intended direction of spin if motor phase wires are connected to OUTA, OUTB and OUTC in wrong sequence or when wrong direction command is issued. Motors with higher inertia coast for a longer period of time. It is recommended to have ISD enabled in applications that require frequent motor starts and stops and use higher inertia motors.

For example, ceiling fan motors have higher inertia due to the fan blades and can coast for long time before stopping.

Step 1: Enable ISD [ISD_EN]

Step 2: Enable Motor ISD Resynchronize [RESYNC_EN]

Note:

Follow the below recommendations if the motor fails to startup.

  1. Increase the Motor Stationary BEMF Threshold [STAT_DETECT_THR].

  2. Increase the Motor Stationary Persistence Time [ISD_STOP_TIME].

  3. Increase the Motor Run Persistence Time [ISD_RUN_TIME].

  4. Increase the Minimum speed threshold to resynchronize to closed loop