SLLSFQ7 November   2023 MCF8329A

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings Comm
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information 1pkg
    5. 6.5 Electrical Characteristics
    6. 6.6 Characteristics of the SDA and SCL bus for Standard and Fast mode
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Three Phase BLDC Gate Drivers
      2. 7.3.2  Gate Drive Architecture
        1. 7.3.2.1 Dead time and Cross Conduction Prevention
      3. 7.3.3  AVDD Linear Voltage Regulator
      4. 7.3.4  DVDD Voltage Regulator
        1. 7.3.4.1 AVDD Powered VREG
        2. 7.3.4.2 External Supply for VREG
        3. 7.3.4.3 External MOSFET for VREG Supply
      5. 7.3.5  Low-Side Current Sense Amplifier
      6. 7.3.6  Device Interface Modes
        1. 7.3.6.1 Interface - Control and Monitoring
        2. 7.3.6.2 I2C Interface
      7. 7.3.7  Motor Control Input Options
        1. 7.3.7.1 Analog-Mode Motor Control
        2. 7.3.7.2 PWM-Mode Motor Control
        3. 7.3.7.3 Frequency-Mode Motor Control
        4. 7.3.7.4 I2C based Motor Control
        5. 7.3.7.5 Input Control Reference Profiles
          1. 7.3.7.5.1 Linear Control Profiles
          2. 7.3.7.5.2 Staircase Control Profiles
          3. 7.3.7.5.3 Forward-Reverse Profiles
        6. 7.3.7.6 Control Input Transfer Function without Profiler
      8. 7.3.8  Bootstrap Capacitor Initial Charging
      9. 7.3.9  Starting the Motor Under Different Initial Conditions
        1. 7.3.9.1 Case 1 – Motor is Stationary
        2. 7.3.9.2 Case 2 – Motor is Spinning in the Forward Direction
        3. 7.3.9.3 Case 3 – Motor is Spinning in the Reverse Direction
      10. 7.3.10 Motor Start Sequence (MSS)
        1. 7.3.10.1 Initial Speed Detect (ISD)
        2. 7.3.10.2 Motor Resynchronization
        3. 7.3.10.3 Reverse Drive
          1. 7.3.10.3.1 Reverse Drive Tuning
        4. 7.3.10.4 Motor Start-up
          1. 7.3.10.4.1 Align
          2. 7.3.10.4.2 Double Align
          3. 7.3.10.4.3 Initial Position Detection (IPD)
            1. 7.3.10.4.3.1 IPD Operation
            2. 7.3.10.4.3.2 IPD Release
            3. 7.3.10.4.3.3 IPD Advance Angle
          4. 7.3.10.4.4 Slow First Cycle Startup
          5. 7.3.10.4.5 Open loop
          6. 7.3.10.4.6 Transition from Open to Closed Loop
      11. 7.3.11 Closed Loop Operation
        1. 7.3.11.1 Closed loop accelerate
        2. 7.3.11.2 Speed PI Control
        3. 7.3.11.3 Current PI Control
        4. 7.3.11.4 Power Loop
        5. 7.3.11.5 Modulation Index Control
      12. 7.3.12 Maximum Torque Per Ampere (MTPA) Control
      13. 7.3.13 Flux Weakening Control
      14. 7.3.14 Motor Parameters
        1. 7.3.14.1 Motor Resistance
        2. 7.3.14.2 Motor Inductance
        3. 7.3.14.3 Motor Back-EMF constant
      15. 7.3.15 Motor Parameter Extraction Tool (MPET)
      16. 7.3.16 Anti-Voltage Surge (AVS)
      17. 7.3.17 Output PWM Switching Frequency
      18. 7.3.18 Active Braking
      19. 7.3.19 Dead Time Compensation
      20. 7.3.20 Voltage Sense Scaling
      21. 7.3.21 Motor Stop Options
        1. 7.3.21.1 Coast (Hi-Z) Mode
        2. 7.3.21.2 Recirculation Mode
        3. 7.3.21.3 Low-Side Braking
        4. 7.3.21.4 Active Spin-Down
      22. 7.3.22 FG Configuration
        1. 7.3.22.1 FG Output Frequency
        2. 7.3.22.2 FG in Open-Loop
        3. 7.3.22.3 FG During Motor Stop
        4. 7.3.22.4 FG Behaviour During Fault
      23. 7.3.23 DC Bus Current Limit
      24. 7.3.24 Protections
        1. 7.3.24.1  PVDD Supply Undervoltage Lockout (PVDD_UV)
        2. 7.3.24.2  AVDD Power on Reset (AVDD_POR)
        3. 7.3.24.3  GVDD Undervoltage Lockout (GVDD_UV)
        4. 7.3.24.4  BST Undervoltage Lockout (BST_UV)
        5. 7.3.24.5  MOSFET VDS Overcurrent Protection (VDS_OCP)
        6. 7.3.24.6  VSENSE Overcurrent Protection (SEN_OCP)
        7. 7.3.24.7  Thermal Shutdown (OTSD)
        8. 7.3.24.8  Hardware Lock Detection Current Limit (HW_LOCK_ILIMIT)
          1. 7.3.24.8.1 HW_LOCK_ILIMIT Latched Shutdown (HW_LOCK_ILIMIT_MODE = 00xxb)
          2. 7.3.24.8.2 HW_LOCK_ILIMIT Automatic recovery (HW_LOCK_ILIMIT_MODE = 01xxb)
          3. 7.3.24.8.3 HW_LOCK_ILIMIT Report Only (HW_LOCK_ILIMIT_MODE = 1000b)
          4. 7.3.24.8.4 HW_LOCK_ILIMIT Disabled (HW_LOCK_ILIMIT_MODE= 1001b to 1111b)
        9. 7.3.24.9  Lock Detection Current Limit (LOCK_ILIMIT)
          1. 7.3.24.9.1 LOCK_ILIMIT Latched Shutdown (LOCK_ILIMIT_MODE = 00xxb)
          2. 7.3.24.9.2 LOCK_ILIMIT Automatic Recovery (LOCK_ILIMIT_MODE = 01xxb)
          3. 7.3.24.9.3 LOCK_ILIMIT Report Only (LOCK_ILIMIT_MODE = 1000b)
          4. 7.3.24.9.4 LOCK_ILIMIT Disabled (LOCK_ILIMIT_MODE = 1xx1b)
        10. 7.3.24.10 Motor Lock (MTR_LCK)
          1. 7.3.24.10.1 MTR_LCK Latched Shutdown (MTR_LCK_MODE = 00xxb)
          2. 7.3.24.10.2 MTR_LCK Automatic Recovery (MTR_LCK_MODE= 01xxb)
          3. 7.3.24.10.3 MTR_LCK Report Only (MTR_LCK_MODE = 1000b)
          4. 7.3.24.10.4 MTR_LCK Disabled (MTR_LCK_MODE = 1xx1b)
        11. 7.3.24.11 Motor Lock Detection
          1. 7.3.24.11.1 Lock 1: Abnormal Speed (ABN_SPEED)
          2. 7.3.24.11.2 Lock 2: Abnormal BEMF (ABN_BEMF)
          3. 7.3.24.11.3 Lock3: No-Motor Fault (NO_MTR)
        12. 7.3.24.12 MPET Faults
        13. 7.3.24.13 IPD Faults
    4. 7.4 Device Functional Modes
      1. 7.4.1 Functional Modes
        1. 7.4.1.1 Sleep Mode
        2. 7.4.1.2 Standby Mode
        3. 7.4.1.3 Fault Reset (CLR_FLT)
    5. 7.5 External Interface
      1. 7.5.1 DRVOFF - Gate Driver Shutdown Functionality
      2. 7.5.2 DAC outputs
      3. 7.5.3 Current Sense Amplifier Output
      4. 7.5.4 Oscillator Source
        1. 7.5.4.1 External Clock Source
    6. 7.6 EEPROM access and I2C interface
      1. 7.6.1 EEPROM Access
        1. 7.6.1.1 EEPROM Write
        2. 7.6.1.2 EEPROM Read
      2. 7.6.2 I2C Serial Interface
        1. 7.6.2.1 I2C Data Word
        2. 7.6.2.2 I2C Write Operation
        3. 7.6.2.3 I2C Read Operation
        4. 7.6.2.4 Examples of I2C Communication Protocol Packets
        5. 7.6.2.5 Internal Buffers
        6. 7.6.2.6 CRC Byte Calculation
    7. 7.7 EEPROM (Non-Volatile) Register Map
      1. 7.7.1 Algorithm_Configuration Registers
      2. 7.7.2 Internal_Algorithm_Configuration Registers
      3. 7.7.3 Hardware_Configuration Registers
      4. 7.7.4 Fault_Configuration Registers
    8. 7.8 RAM (Volatile) Register Map
      1. 7.8.1 Fault_Status Registers
      2. 7.8.2 Algorithm_Control Registers
      3. 7.8.3 System_Status Registers
      4. 7.8.4 Device_Control Registers
      5. 7.8.5 Algorithm_Variables Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1.      Detailed Design Procedure
      2.      Bootstrap Capacitor and GVDD Capacitor Selection
      3. 8.2.1 Selection of External MOSFET for VREG Power Supply
      4.      Gate Drive Current
      5.      Gate Resistor Selection
      6.      System Considerations in High Power Designs
      7.      Capacitor Voltage Ratings
      8.      External Power Stage Components
      9. 8.2.2 Application curves
        1. 8.2.2.1 Motor startup
        2.       High speed (1.8 kHz) operation
        3.       Active Braking for faster deceleration
        4. 8.2.2.2 Dead Time compensation
  10. 9 Power Supply Recommendations
    1. 9.1 Bulk Capacitance
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
      1. 10.3.1 Power Dissipation
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.18 Active Braking

Decelerating the motor quickly requires the motor mechanical energy to be extracted from the rotor in a fast and controlled manner. However, the DC supply voltage increases if the motor mechanical energy is returned to the power supply during the deceleration process. MCF8329A is capable of decelerating the motor quickly without pumping energy back into the supply voltage by using a novel technique called active braking. ACTIVE_BRAKE_EN should be set to 1b to enable active braking and prevent DC bus voltage spike during fast motor deceleration. Active braking can also be used during reverse drive (see Reverse Drive) or motor stop (see Active Spin-Down) to reduce the motor speed quickly without DC voltage spike.

The maximum limit on the current sourced from the DC bus (idc_ref) during active braking can be configured using ACTIVE_BRAKE_CURRENT_LIMIT. The power flow control during active braking is achieved by using both Q-axis (iq) and D-axis (id) components of current. The D-axis current reference (id_ref) is generated from the error between DC bus current limit (idc_ref) and the estimated DC bus current (idc) using a PI controller. The idc value is estimated from the measured phase currents, phase voltage and DC bus voltage, using power balance equation (equating the instantaneous DC bus power to sum of all three instantaneous phase power assuming 100% efficiency). During active braking, the DC bus current limit (idc_ref) starts from zero and linearly increases to ACTIVE_BRAKE_CURRENT_LIMIT with current slew rate as defined by ACTIVE_BRAKE_BUS_CURRENT_SLEW_RATE. The gain constants of PI controller can be configured using ACTIVE_BRAKE_KP and ACTIVE_BRAKE_KI. Figure 7-46 shows the active braking id current control loop.

GUID-DE38514C-230F-43C4-86FC-A5E68BE4D44E-low.svgFigure 7-39 Active Braking Current Control Loop for id_ref

ACTIVE_BRAKE_SPEED_DELTA_LIMIT_ENTRY sets the minimum difference between the initial and target speed above which active braking will be entered. For example, consider ACTIVE_BRAKE_SPEED_DELTA_LIMIT_ENTRY is set to 10%; if the initial speed is 100% and target speed is set to 95%, MCF8329A uses AVS instead of active braking to reach 95% speed since the difference in commanded speed change (5%) is less than ACTIVE_BRAKE_SPEED_DELTA_LIMIT_ENTRY (10%).

ACTIVE_BRAKE_SPEED_DELTA_LIMIT_EXIT sets the difference between the current and target speed below which active braking will be exited. For example, consider ACTIVE_BRAKE_SPEED_DELTA_LIMIT_EXIT is set to 5%; if the initial motor speed is 100% and target speed is set to 10%, MCF8329A uses active braking to reduce the motor speed to 15%; upon reaching 15% speed, MCF8329A exits active braking and uses AVS to decelerate the motor speed to 10%.

ACTIVE_BRAKE_MOD_INDEX_LIMIT sets the modulation index below which active braking will be used. For example, consider ACTIVE_BRAKE_MOD_INDEX_LIMIT is set to 50%, ACTIVE_BRAKE_SPEED_DELTA_LIMIT_ENTRY is set to 5%, ACTIVE_BRAKE_SPEED_DELTA_LIMIT_EXIT is set to 2.5%. If the initial motor speed is at 70% (corresponding modulation index is 90%) and target speed is 40% (corresponding modulation index is 60%), MCF8329A uses AVS to decelerate the motor till target speed of 40% since the modulation index (60%) corresponding to final speed is higher than ACTIVE_BRAKE_MOD_INDEX_LIMIT of 50%. In the same case, if final speed command is 10% (corresponding modulation index is 30%), MCF8329A uses AVS till 30% speed (corresponding modulation index is 50%), switches to active braking from 30% to 15% speed (final speed of 10% + ACTIVE_BRAKE_SPEED_DELTA_LIMIT_EXIT of 5%) and uses AVS again from 15% to 10% speed to complete the active braking. TI recommends starting active braking tuning with ACTIVE_BRAKE_MOD_INDEX_LIMIT set to 100%; if there is a DC bus voltage spike observed during active braking, reduce ACTIVE_BRAKE_MOD_INDEX_LIMIT in steps so as to eliminate this voltage spike. If ACTIVE_BRAKE_MOD_INDEX_LIMIT is set to 0%, MCF8329A decelerates in AVS (even when ACTIVE_BRAKE_EN is set to 1b) in the forward direction; in reverse direction (during direction change), ACTIVE_BRAKE_MOD_INDEX_LIMIT is not applicable and therefore MCF8329A decelerates in active braking.

Note:
  1. ACTIVE_BRAKE_SPEED_DELTA_LIMIT_ENTRY, ACTIVE_BRAKE_SPEED_DELTA_LIMIT_EXIT and ACTIVE_BRAKE_MOD_INDEX_LIMIT are applicable only during deceleration in forward direction and not used during direction change.
  2. ACTIVE_BRAKE_SPEED_DELTA_LIMIT_ENTRY should be set higher than ACTIVE_BRAKE_SPEED_DELTA_LIMIT_EXIT for active braking operation.
  3. During active (or closed loop) braking, Iq_ref is clamped to -ILIMIT. This (Iq_ref being clamped to -ILIMIT) may result in the speed PI loop getting saturated and SPEED_LOOP_SATURATION bit getting set to 1b during deceleration. This bit is automatically set to 0b once the deceleration is completed and the speed PI loop is out of saturation. Hence, speed loop saturation fault should be ignored during deceleration.
  4. Active braking is only available in speed control mode.