SLLU364 may   2023 MCT8315A

 

  1.   1
  2.   Abstract
  3. 1Revision History
  4.   Trademarks
  5. 2Introduction
    1. 2.1 Hardware and GUI setup
      1. 2.1.1 Jumper Configuration
      2. 2.1.2 External Connections
      3. 2.1.3 Connecting to the GUI
        1. 2.1.3.1 Connect to computer
        2. 2.1.3.2 Connect to the GUI
        3. 2.1.3.3 Verify Hardware Connection
  6. 3Essential Controls
    1. 3.1 Recommended Default Values based on application
    2. 3.2 Device and Pin Configuration
      1. 3.2.1 Speed input mode
    3. 3.3 Algorithm configuration – Motor speed
      1. 3.3.1 Maximum motor electrical speed (Hz)
    4. 3.4 Control Configuration
      1. 3.4.1 Cycle by cycle current limit (ILIMIT)
    5. 3.5 Testing for successful startup into closed loop
    6. 3.6 Fault handling
      1. 3.6.1 Abnormal Speed [ABN_SPEED]
      2. 3.6.2 Loss of Sync [LOSS_OF_SYNC]
      3. 3.6.3 No Motor Fault [NO_MTR]
      4. 3.6.4 Cycle by cycle current limit [CBC_ILIMIT]
  7. 4Basic Controls
    1. 4.1 Device and pin configuration
      1. 4.1.1 Power saver or sleep mode for battery operated applications
      2. 4.1.2 Direction and Brake pin override
    2. 4.2 System level configuration
      1. 4.2.1 Tracking motor speed feedback in real time
      2. 4.2.2 Monitoring power supply voltage fluctuations for normal motor operation
    3. 4.3 Control configurations
      1. 4.3.1  Initial speed detection of the motor for reliable motor resynchronization
      2. 4.3.2  Unidirectional motor drive detecting backward spin
      3. 4.3.3  Preventing back spin of rotor during startup
      4. 4.3.4  Faster startup timing
      5. 4.3.5  Improving speed regulation
      6. 4.3.6  Stopping motor quickly
      7. 4.3.7  Faster deceleration
      8. 4.3.8  Preventing supply voltage overshoot during motor stop and deceleration
      9. 4.3.9  Protecting against rotor lock or stall condition
      10. 4.3.10 Maximizing thermal efficiency and increasing thermal performance
      11. 4.3.11 Mitigating Electromagnetic Interference (EMI)
      12. 4.3.12 Improving Motor efficiency
      13. 4.3.13 Limiting and regulating supply power

2 Introduction

The MCT8315A provides three half-H-bridge integrated MOSFET drivers with sensorless trapezoidal control to drive a three-phase brushless DC (BLDC) motor at 12-V/24-V DC rails or battery powered applications. The device integrates three current-sense amplifiers (CSA) with integrated current sense for sensing the three phase currents of BLDC motors to achieve optimum trapezoidal control. Simplified schematic of MCT8315A is shown in Figure 2-1.

GUID-20220803-SS0I-XZFK-CGC2-JZPD9JN7VSXL-low.svgFigure 2-1 Simplified Schematic of MCT8315A.

This tuning guide provides the steps to tune a 3-phase BLDC motor using the MCT8315A. The tuning process is classified into two sections: Essential controls and Basic controls. This process is also detailed in the Guided tuning section in the GUI.

  • Essential controls: Tuning steps to successfully spin the motor in closed loop

  • Basic controls: Tuning steps to conform to use-case and explore features in the device