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

8.3.4 Step-Down Mixed-Mode Buck Regulator

The MCT8315Z has an integrated mixed-mode buck regulator to supply regulated 3.3-V or 5.0-V power for an external controller or system voltage rail. Additionally, the buck output can also be configured to 4.0-V or 5.7-V for supporting the extra headroom for external LDO for generating a 3.3-V or 5.0-V supplies. The output voltage of the buck converter is set by BUCK_SEL bits in the MCT8315ZR device (SPI variant). The output voltage of the buck converter in MCT8315ZH (hardware variant) is always set to 5.0-V.

The buck regulator has a low quiescent current of ~1-2 mA during light loads to prolong battery life. The device improves performance during line and load transients by implementing a pulse-frequency current-mode control scheme which requires less output capacitance and simplifies frequency compensation design.

To disable the buck regulator, set the BUCK_DIS bit to 1b in MCT8315ZR (SPI variant). The buck regulator cannot be disabled in MCT8315ZH (hardware variant). MCT8315ZT has no buck regulator.

Note: If the buck regulator is unused in MCT8315ZH, the buck pins SW_BK, GND_BK, and FB_BK cannot be left floating or connected to ground. The buck regulator components LBK/RBK and CBK must be connected in hardware.

Table 8-5 Recommended settings for Buck Regulator
Buck Mode Buck output voltage Max output current from AVDD (IAVDD) Max output current from Buck (IBK) Buck current limit AVDD power sequencing
Inductor - 47 μH 3.3-V or 4.0-V or 5.0-V or 5.7-V 30 mA 200 mA 600 mA (BUCK_CL = 0b) Not supported (BUCK_PS_DIS = 1)
Inductor - 47 μH 5.0-V or 5.7-V 30 mA 200 mA - IAVDD 600 mA (BUCK_CL = 0b) Supported (BUCK_PS_DIS = 0)
Inductor - 22 μH 3.3-V or 4.0-V or 5.0-V or 5.7-V 30 mA 50 mA 150 mA (BUCK_CL = 1b) Not supported (BUCK_PS_DIS = 1)
Inductor - 22 μH 5.0-V or 5.7-V 30 mA 50 mA - IAVDD 150 mA (BUCK_CL = 1b) Supported (BUCK_PS_DIS = 0)
Resistor - 22 Ω 3.3-V or 4.0-V or 5.0-V or 5.7-V 30 mA 40 mA 150 mA (BUCK_CL = 1b) Not supported (BUCK_PS_DIS = 1)
Resistor - 22 Ω 5.0-V or 5.7-V 30 mA 40 mA - IAVDD 150 mA (BUCK_CL = 1b) Supported (BUCK_PS_DIS = 0)