SLLSFT3 November   2025 MC121-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings Auto
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Timing Requirements
    7. 5.7 Timing Diagrams
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Motor Control
        1. 6.3.1.1 Duty Input
        2. 6.3.1.2 Duty Curve
        3. 6.3.1.3 Motor Start, Speed Change, and Stop
        4. 6.3.1.4 Open-Loop (Duty Cycle) Control
        5. 6.3.1.5 Closed-Loop (Speed) Control
        6. 6.3.1.6 Commutation
          1. 6.3.1.6.1 Hall Sensor
            1. 6.3.1.6.1.1 Field Direction Definition
            2. 6.3.1.6.1.2 Internal Hall Latch Sensor Output
          2. 6.3.1.6.2 Hall Offset
          3. 6.3.1.6.3 Square Commutation
          4. 6.3.1.6.4 Soft Commutation
        7. 6.3.1.7 PWM Modulation Modes
      2. 6.3.2 Protections
        1. 6.3.2.1 Locked Rotor Protection
        2. 6.3.2.2 Current Limit
        3. 6.3.2.3 Overcurrent Protection (OCP)
        4. 6.3.2.4 VM Undervoltage Lockout (UVLO)
        5. 6.3.2.5 VM Over Voltage Protection (OVP)
        6. 6.3.2.6 Thermal Shutdown (TSD)
        7. 6.3.2.7 Integrated Supply (VM) Clamp
    4. 6.4 Device Functional Modes
      1. 6.4.1 Active Mode
      2. 6.4.2 Sleep and Standby Mode
      3. 6.4.3 Fault Mode
      4. 6.4.4 Test Mode and One-Time Programmable Memory
    5. 6.5 Programming
      1. 6.5.1 I2C Communication
        1. 6.5.1.1 I2C Read
        2. 6.5.1.2 I2C Write
  8. 7 Register Map
    1. 7.1 USR_OTP Registers
    2. 7.2 USR_TM Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 External Components
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Bulk Capacitance
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
  • DYM|6
  • DEZ|6
サーマルパッド・メカニカル・データ
発注情報
6.3.1.6.3 Square Commutation

Square commutation is a simple commutation scheme provided by MC121-Q1 for maximum torque/speed operation. Figure 6-14 shows the driver output voltage relative to the Hall sensor signal in square commutation.

MC121-Q1 Square Commutation Timing Waveform Figure 6-14 Square Commutation Timing Waveform

In square commutation, the output duty cycle remains constant at DOUT with respect to the electrical angle (θElectrical). The signal from the Hall sensor and HALL_INVERT bit determines the OUTx terminal that switches at the commanded duty cycle and the OUTx terminal that is pulled to GND during the 180° electrical half cycle, θEHC.

The demagnetization state, θDEMAG, occurs at the end of the electrical half cycle and is determined by the DEMAG_TIME bits. The purpose of demagnetization is to reduce the motor current to zero and demagnetize the stator windings before reversing the OUTx voltage polarity due to a commutation event. Demagnetization minimizes voltage spikes on the VM supply and OUTx during commutation. Demagnetization also improves efficiency by reducing motor current spikes around the commutation region when back-EMF is minimal. PWM_MODE sets synchronous, asynchronous, or hybrid modulation for motor current during PWM OFF time and θDEMAG time, as described in Section 6.3.1.7. Figure 6-15, Figure 6-16, and Figure 6-17 show timing diagrams for asynchronous, synchronous, and hybrid recirculation states during θDEMAG respectively.

MC121-Q1 Detailed Timing Diagram for Square Commutation Using Asynchronous Mode for θDEMAG Figure 6-15 Detailed Timing Diagram for Square Commutation Using Asynchronous Mode for θDEMAG
MC121-Q1 Detailed Timing Diagram for Square Commutation Using Synchronous Mode for θDEMAG Figure 6-16 Detailed Timing Diagram for Square Commutation Using Synchronous Mode for θDEMAG
MC121-Q1 Detailed Timing Diagram for Square Commutation Using Hybrid Mode for θDEMAG Figure 6-17 Detailed Timing Diagram for Square Commutation Using Hybrid Mode for θDEMAG

The demag time (DEMAG_TIME) can be set to a fixed time or can be automatically determined. When the AUTO_DEMAG_EN is set to 0x0, the demagnatization time is constant across operating conditions, and the DEMAG_TIME bits determine the θDEMAG based on speed of the motor. When the AUTO_DEMAG_EN is set to 0x1, the driver automatically adjusts the θDEMAG angle to optimize the demagnetization duration based on the speed of the motor.