SLLSFQ3 January   2023 MCT8329A

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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
  7. 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 Signal 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  Starting the Motor Under Different Initial Conditions
        1. 7.3.8.1 Case 1 – Motor is Stationary
        2. 7.3.8.2 Case 2 – Motor is Spinning in the Forward Direction
        3. 7.3.8.3 Case 3 – Motor is Spinning in the Reverse Direction
      9. 7.3.9  Motor Start Sequence (MSS)
        1. 7.3.9.1 Initial Speed Detect (ISD)
        2. 7.3.9.2 Motor Resynchronization
        3. 7.3.9.3 Reverse Drive
        4. 7.3.9.4 Motor Start-up
          1. 7.3.9.4.1 Align
          2. 7.3.9.4.2 Double Align
          3. 7.3.9.4.3 Initial Position Detection (IPD)
            1. 7.3.9.4.3.1 IPD Operation
            2. 7.3.9.4.3.2 IPD Release
            3. 7.3.9.4.3.3 IPD Advance Angle
          4. 7.3.9.4.4 Slow First Cycle Startup
          5. 7.3.9.4.5 Open loop
          6. 7.3.9.4.6 Transition from Open to Closed Loop
      10. 7.3.10 Closed Loop Operation
        1. 7.3.10.1 120o Commutation
          1. 7.3.10.1.1 High-Side Modulation
          2. 7.3.10.1.2 Low-Side Modulation
          3. 7.3.10.1.3 Mixed Modulation
        2. 7.3.10.2 Variable Commutation
        3. 7.3.10.3 Lead Angle Control
        4. 7.3.10.4 Closed loop accelerate
      11. 7.3.11 Speed Loop
      12. 7.3.12 Power Loop
      13. 7.3.13 Anti-Voltage Surge (AVS)
      14. 7.3.14 Output PWM Switching Frequency
      15. 7.3.15 Fast Start-up (< 50 ms)
        1. 7.3.15.1 BEMF Threshold
        2. 7.3.15.2 Dynamic Degauss
      16. 7.3.16 Fast Deceleration
      17. 7.3.17 Dynamic Voltage Scaling
      18. 7.3.18 Motor Stop Options
        1. 7.3.18.1 Coast (Hi-Z) Mode
        2. 7.3.18.2 Recirculation Mode
        3. 7.3.18.3 Low-Side Braking
        4. 7.3.18.4 High-Side Braking
        5. 7.3.18.5 Active Spin-Down
      19. 7.3.19 FG Configuration
        1. 7.3.19.1 FG Output Frequency
        2. 7.3.19.2 FG in Open-Loop
        3. 7.3.19.3 FG During Motor Stop
        4. 7.3.19.4 FG Behaviour During Fault
      20. 7.3.20 Protections
        1. 7.3.20.1  PVDD Supply Undervoltage Lockout (PVDD_UV)
        2. 7.3.20.2  AVDD Power on Reset (AVDD_POR)
        3. 7.3.20.3  GVDD Undervoltage Lockout (GVDD_UV)
        4. 7.3.20.4  BST Undervoltage Lockout (BST_UV)
        5. 7.3.20.5  MOSFET VDS Overcurrent Protection (VDS_OCP)
        6. 7.3.20.6  VSENSE Overcurrent Protection (SEN_OCP)
        7. 7.3.20.7  Thermal Shutdown (OTSD)
        8. 7.3.20.8  Cycle-by-Cycle (CBC) Current Limit (CBC_ILIMIT)
          1. 7.3.20.8.1 CBC_ILIMIT Automatic Recovery next PWM Cycle (CBC_ILIMIT_MODE = 000xb)
          2. 7.3.20.8.2 CBC_ILIMIT Automatic Recovery Threshold Based (CBC_ILIMIT_MODE = 001xb)
          3. 7.3.20.8.3 CBC_ILIMIT Automatic Recovery after 'n' PWM Cycles (CBC_ILIMIT_MODE = 010xb)
          4. 7.3.20.8.4 CBC_ILIMIT Report Only (CBC_ILIMIT_MODE = 0110b)
          5. 7.3.20.8.5 CBC_ILIMIT Disabled (CBC_ILIMIT_MODE = 0111b or 1xxxb)
        9. 7.3.20.9  Lock Detection Current Limit (LOCK_ILIMIT)
          1. 7.3.20.9.1 LOCK_ILIMIT Latched Shutdown (LOCK_ILIMIT_MODE = 00xxb)
          2. 7.3.20.9.2 LOCK_ILIMIT Automatic Recovery (LOCK_ILIMIT_MODE = 01xxb)
          3. 7.3.20.9.3 LOCK_ILIMIT Report Only (LOCK_ILIMIT_MODE = 1000b)
          4. 7.3.20.9.4 LOCK_ILIMIT Disabled (LOCK_ILIMIT_MODE = 1xx1b)
        10. 7.3.20.10 Motor Lock (MTR_LCK)
          1. 7.3.20.10.1 MTR_LCK Latched Shutdown (MTR_LCK_MODE = 00xxb)
          2. 7.3.20.10.2 MTR_LCK Automatic Recovery (MTR_LCK_MODE= 01xxb)
          3. 7.3.20.10.3 MTR_LCK Report Only (MTR_LCK_MODE = 1000b)
          4. 7.3.20.10.4 MTR_LCK Disabled (MTR_LCK_MODE = 1xx1b)
        11. 7.3.20.11 Motor Lock Detection
          1. 7.3.20.11.1 Lock 1: Abnormal Speed (ABN_SPEED)
          2. 7.3.20.11.2 Lock 2: Loss of Sync (LOSS_OF_SYNC)
          3. 7.3.20.11.3 Lock3: No-Motor Fault (NO_MTR)
        12. 7.3.20.12 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 Fault_Configuration Registers
      3. 7.7.3 Hardware_Configuration Registers
      4. 7.7.4 Gate_Driver_Configuration Registers
    8. 7.8 RAM (Volatile) Register Map
      1. 7.8.1 Fault_Status Registers
      2. 7.8.2 System_Status Registers
      3. 7.8.3 Algo_Control Registers
      4. 7.8.4 Device_Control Registers
      5. 7.8.5 Algorithm_Variables Registers
  8. 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. 8.2.2.2 120o and variable commutation
        3. 8.2.2.3 Faster startup time
        4. 8.2.2.4 Setting the BEMF threshold
        5. 8.2.2.5 Maximum speed
        6. 8.2.2.6 Faster deceleration
  9. 9 Power Supply Recommendations
    1. 9.1 Bulk Capacitance
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
      1. 10.3.1 Power Dissipation
  11. 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
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.16 Fast Deceleration

MCT8329A has the capability to decelerate a motor quickly (100% to 10% speed reduction within tens of ms) without pumping energy back into the input DC supply using the fast deceleration feature in conjunction with the AVS feature. The fast deceleration feature can be enabled by setting FAST_DECEL_EN to 1b; AVS_EN should be set to 1b to prevent energy pump-back into the input DC supply. This combination enables a linear braking effect resulting in a fast and smooth speed reduction without energy pump-back into the DC input supply. This feature combination can also be used during reverse drive (see Reverse Drive) or motor stop (see Active Spin-Down) to reduce the motor speed quickly without energy pump-back into the DC input supply.

Note: Fast deceleration feature is available only in bi-directional CSA mode. The feature is not available in uni-directional CSA mode.

The deceleration time can be controlled by appropriately configuring the current limit during deceleration, FAST_DECEL_CURR_LIM. A higher current limit results in a lower deceleration time and vice-versa. A higher than necessary current limit setting may result in motor stall faults, at low target speeds, due to excessive braking torque. This can also lead to higher losses in the external FETs, especially in repeated acceleration-deceleration cycles. Therefore, the FAST_DECEL_CURR_LIM should be chosen appropriately, so as to decelerate within the required time without resulting in stall faults or overheating.

FAST_BRK_DELTA is used to configure the target speed hysteresis band to exit the fast deceleration mode and re-enter motoring mode when motor reaches the target speed. For example, if FAST_BRK_DELTA is set to 1%, the fast deceleration is deemed complete when motor speed reaches within 1% of target speed. Setting a higher value for FAST_BRK_DELTA may eliminate motor stall faults, especially when high FAST_DECEL_CURR_LIM values are used. Setting a higher value for FAST_BRK_DETLA will also result in higher speed error between target speed and motor speed at the end of deceleration mode - motor will eventually reach the target speed once motoring mode is resumed. FAST_DECEL_CURR_LIM and FAST_BRK_DELTA should be configured in tandem to optimize between lower deceleration time and reliable (no stall faults) deceleration profile.

FAST_DEC_DUTY_THR configures the speed below which fast deceleration will be implemented. For example, if FAST_DEC_DUTY_THR is set to 70%, any deceleration from speeds above 70% will not use fast deceleration until the speed goes below 70%. FAST_DEC_DUTY_WIN is used to set the minimum deceleration window (initial speed - target speed) below which fast deceleration will not be implemented. For example, if FAST_DEC_DUTY_WIN is set to 15% and 50%->40% deceleration command is received, fast deceleration is not used to reduce the speed from 50% to 40% since the deceleration window (10%) is smaller than FAST_DEC_DUTY_WIN.

MCT8329A provides a dynamic current limit option during fast deceleration to improve the stability of fast deceleration when braking to very low speeds; using this feature the current limit during fast deceleration can be reduced as the motor speed decreases. This feature can be enabled by setting DYNAMIC_BRK_CURR to 1b. The current limit at the start of fast deceleration (at FAST_DEC_DUTY_THR) is configured by FAST_DECEL_CURR_LIM and the current limit at zero speed is configured by DYN_BRK_CURR_LOW_LIM; the current limit during fast deceleration varies linearly with speed between these two operating points when dynamic current limit is enabled. If dynamic current limit is disabled, current limit during fast deceleration stays constant and is configured by FAST_DECEL_CURR_LIM.