SLVSH53 December   2023 MCT8315Z

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 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 SPI Timing Requirements
    7. 7.7 SPI Secondary Device Mode Timings
    8. 7.8 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Output Stage
      2. 8.3.2  PWM Control Mode (1x PWM Mode)
        1. 8.3.2.1 Analog Hall Input Configuration
        2. 8.3.2.2 Digital Hall Input Configuration
        3. 8.3.2.3 Asynchronous Modulation
        4. 8.3.2.4 Synchronous Modulation
        5. 8.3.2.5 Motor Operation
      3. 8.3.3  Device Interface Modes
        1. 8.3.3.1 Serial Peripheral Interface (SPI)
        2. 8.3.3.2 Hardware Interface
      4. 8.3.4  Step-Down Mixed-Mode Buck Regulator
        1. 8.3.4.1 Buck in Inductor Mode
        2. 8.3.4.2 Buck in Resistor mode
        3. 8.3.4.3 Buck Regulator with External LDO
        4. 8.3.4.4 AVDD Power Sequencing on Buck Regulator
        5. 8.3.4.5 Mixed mode Buck Operation and Control
      5. 8.3.5  AVDD Linear Voltage Regulator
      6. 8.3.6  Charge Pump
      7. 8.3.7  Slew Rate Control
      8. 8.3.8  Cross Conduction (Dead Time)
      9. 8.3.9  Propagation Delay
        1. 8.3.9.1 Driver Delay Compensation
      10. 8.3.10 Pin Diagrams
        1. 8.3.10.1 Logic Level Input Pin (Internal Pulldown)
        2. 8.3.10.2 Logic Level Input Pin (Internal Pullup)
        3. 8.3.10.3 Open Drain Pin
        4. 8.3.10.4 Push Pull Pin
        5. 8.3.10.5 Four Level Input Pin
        6. 8.3.10.6 Seven Level Input Pin
      11. 8.3.11 Active Demagnetization
        1. 8.3.11.1 Automatic Synchronous Rectification Mode (ASR Mode)
          1. 8.3.11.1.1 Automatic Synchronous Rectification in Commutation
          2. 8.3.11.1.2 Automatic Synchronous Rectification in PWM Mode
        2. 8.3.11.2 Automatic Asynchronous Rectification Mode (AAR Mode)
      12. 8.3.12 Cycle-by-Cycle Current Limit
        1. 8.3.12.1 Cycle by Cycle Current Limit with 100% Duty Cycle Input
      13. 8.3.13 Hall Comparators (Analog Hall Inputs)
      14. 8.3.14 Advance Angle
      15. 8.3.15 FGOUT Signal
      16. 8.3.16 Protections
        1. 8.3.16.1  VM Supply Undervoltage Lockout (NPOR)
        2. 8.3.16.2  AVDD Undervoltage Lockout (AVDD_UV)
        3. 8.3.16.3  Buck Undervoltage Lockout (BUCK_UV)
        4. 8.3.16.4  VCP Charge Pump Undervoltage Lockout (CPUV)
        5. 8.3.16.5  Overvoltage Protection (OVP)
        6. 8.3.16.6  Overcurrent Protection (OCP)
          1. 8.3.16.6.1 OCP Latched Shutdown (OCP_MODE = 00b)
          2. 8.3.16.6.2 OCP Automatic Retry (OCP_MODE = 01b)
        7. 8.3.16.7  Buck Overcurrent Protection
        8. 8.3.16.8  Motor Lock (MTR_LOCK)
          1. 8.3.16.8.1 MTR_LOCK Latched Shutdown (MTR_LOCK_MODE = 00b)
          2. 8.3.16.8.2 MTR_LOCK Automatic Retry (MTR_LOCK_MODE = 01b)
          3. 8.3.16.8.3 MTR_LOCK Report Only (MTR_LOCK_MODE= 10b)
          4. 8.3.16.8.4 MTR_LOCK Disabled (MTR_LOCK_MODE = 11b)
          5. 8.3.16.8.5 75
        9. 8.3.16.9  Thermal Warning (OTW)
        10. 8.3.16.10 Thermal Shutdown (OTSD)
          1. 8.3.16.10.1 OTSD FET
          2. 8.3.16.10.2 OTSD (Non-FET)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Functional Modes
        1. 8.4.1.1 Sleep Mode
        2. 8.4.1.2 Operating Mode
        3. 8.4.1.3 Fault Reset (CLR_FLT or nSLEEP Reset Pulse)
      2. 8.4.2 DRVOFF
    5. 8.5 SPI Communication
      1. 8.5.1 Programming
        1. 8.5.1.1 SPI Format
    6. 8.6 Register Map
      1. 8.6.1 STATUS Registers
      2. 8.6.2 CONTROL Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Hall Sensor Configuration and Connection
      1. 9.2.1 Typical Configuration
      2. 9.2.2 Open Drain Configuration
      3. 9.2.3 Series Configuration
      4. 9.2.4 Parallel Configuration
    3. 9.3 Typical Applications
      1. 9.3.1 Three-Phase Brushless-DC Motor Control With Current Limit
        1. 9.3.1.1 Detailed Design Procedure
          1. 9.3.1.1.1 Motor Voltage
          2. 9.3.1.1.2 Using Active Demagnetization
          3. 9.3.1.1.3 Using Delay Compensation
          4. 9.3.1.1.4 Using the Buck Regulator
          5. 9.3.1.1.5 Power Dissipation and Junction Temperature Losses
        2. 9.3.1.2 Application Curves
  11. 10Power Supply Recommendations
    1. 10.1 Bulk Capacitance
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
      1. 11.3.1 Power Dissipation
  13. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.3.1.1.4 Using the Buck Regulator

In MCT8315Z, the buck regulator components must be populated whether the buck is used or unused.

If unused, Resistor Mode should be configured by placing a small value resistor of 22-Ω for RBK and a 10-V rated, 22-µF capacitor for CBK­ to minimize board space and reduce component cost. To disable the buck regulator, set the BUCK_DIS in the SPI variant. The buck cannot be disabled in the Hardware variant.

If the buck regulator is used, either the Inductor or Resistor Mode can be selected. Inductor Mode allows a 22-µH or 47-µH inductor be used for LBK. CBK­ is recommended to be 22-µF. Make sure an appropriate inductor is chosen to allow for maximum peak saturation current at a 20% inductance drop since the buck can supply up to 600-mA external current.

Resistor Mode allows for power to be dissipated in an external resistor if the load requirement is less than 40-mA. Make sure the resistor is rated for the power dissipation required at worst case VM voltage dropout. See Equation 6, Equation 7, and Equation 8 to calculate the resistor power rating required for a 24-V rated system, 3.3V buck output voltage, and 20-mA load current.

Equation 6. PRBK>VM-VBK×IBK
Equation 7. PRBK> 24V-3.3V×20mA
Equation 8. PR_BK>0.434W