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

Bootstrap Capacitor and GVDD Capacitor Selection

The bootstrap capacitor must be sized to maintain the bootstrap voltage above the undervoltage lockout for normal operation. Equation 13 calculates the maximum allowable voltage drop across the bootstrap capacitor:

Equation 13. GUID-20200927-CA0I-XQLZ-MPTJ-QHB8BMDQLKGS-low.gif

ΔVBSTX=12 V – 0.85 V – 4.45 V = 6.7 V

where

  • VGVDD is the supply voltage of the gate drive
  • VBOOTD is the forward voltage drop of the bootstrap diode
  • VBSTUV is the threshold of the bootstrap undervoltage lockout

In the example, allowed voltage drop across bootstrap capacitor is 6.7 V. It is generally recommended that ripple voltage on both the bootstrap capacitor and GVDD capacitor should be minimized as much as possible. Many of commercial, industrial, and automotive applications use ripple value between 0.5 V to 1 V.

The total charge needed per switching cycle can be estimated with Equation 14:

Equation 14. Q T O T = Q G + I L B S _ T R A N f S W

QTOT=54 nC + 115 μA/20 kHz = 54 nC + 5.8 nC = 59.8nC

where

  • QG is the total MOSFET gate charge
  • ILBS_TRAN is the bootstrap pin leakage current
  • fSW is the is the PWM frequency

The minimum bootstrap capacitor can then be estimated as below assuming 1V of ΔVBSTx:

Equation 15. GUID-20200927-CA0I-34PB-JZQV-BTKNMXGBXPBL-low.gif

CBST_MIN= 59.8 nC / 1 V = 59.8 nF

The calculated value of minimum bootstrap capacitor is 59.8 nF. It should be noted that, this value of capacitance is needed at full bias voltage. In practice, the value of the bootstrap capacitor must be greater than calculated value to allow for situations where the power stage may skip pulse due to various transient conditions. It is recommended to use a 100 nF bootstrap capacitor in this example. It is also recommenced to include enough margin and place the bootstrap capacitor as close to the BSTx and SHx pins as possible.

Equation 16. GUID-20201221-CA0I-JW7J-DPTD-GFN8RP35WWVZ-low.gif

CGVDD= 10*100 nF= 1 μF

For this example application, choose a 1-µF CGVDD capacitor. Choose a capacitor with a voltage rating at least twice the maximum voltage that it will be exposed to because most ceramic capacitors lose significant capacitance when biased. This value also improves the long-term reliability of the system.

Note: For higher power system requiring 100% duty cycle support for longer duration it is recommended to use CBSTx of ≥1μF and CGVDD of ≥10 μF.