SLUUDH9 April   2026 MCF8329HS-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Spinning the motor
    1. 2.1 Connecting to the GUI
    2. 2.2 SmartTune
      1. 2.2.1 SmartTune Execution
    3. 2.3 Manual Tuning
      1. 2.3.1 Loading Recommended Default Values
      2. 2.3.2 Setting Base Current
      3. 2.3.3 Setting Current Limits
      4. 2.3.4 Setting Voltage Limits
      5. 2.3.5 Maximum Electrical Speed (Hz)
      6. 2.3.6 Input the Motor's Phase Resistance, Inductance and BEMF Constant
      7. 2.3.7 Speed loop Manual Tuning
    4. 2.4 Testing for Successful Startup Into Closed Loop
  6. 3Basic Controls
    1. 3.1 Speed Input Mode
    2. 3.2 Preventing Back Spin of Rotor During Startup
    3. 3.3 Faster Startup Timing
    4. 3.4 Improving Current and Speed Regulation
    5. 3.5 Limiting and Regulating Supply Power
    6. 3.6 MTPA Tuning
    7. 3.7 Motor Studio Optimization Wizards
  7. 4Fault Handling
    1. 4.1 Abnormal BEMF Fault [ABN_BEMF]
    2. 4.2 Lock Current Limit [LOCK_LIMIT]
    3. 4.3 Hardware Lock Current Limit [HW_LOCK_LIMIT]
    4. 4.4 No Motor Fault [NO_MTR]
    5. 4.5 Abnormal Speed [ABN_SPEED]
  8. 5Hardware Design and Setup
    1. 5.1 Board Design
      1. 5.1.1 External MOSFET Selection
      2. 5.1.2 Gate Resistor Selection
      3. 5.1.3 Bootstrap and GVDD Capacitor Selection
      4. 5.1.4 Current Shunt Resistor Selection
      5. 5.1.5 VREG MOSFET Selection
      6. 5.1.6 Additional External Power Stage Components

2.3.7 Speed loop Manual Tuning

For applications that require better speed regulation, it is recommended to tune Speed loop PI controllers [SPD_LOOP_KP] and [SPD_LOOP_KI]. Kp coefficient of speed loop [SPD_LOOP_KP] controls the settling time and speed overshoots. Ki coefficient of Speed loop [SPD_LOOP_KI] controls speed overshoot and ensures regulation of speed at set value and drives the error to zero. Speed loop PI controller gains can either be auto-tuned by MCF8329HS or tuned manually.

Manual Tuning: Use the following steps to tune Speed loop PI controller gains manually:

  1. Set the control mode [CTRL_MODE] to modulation index control (11b).
  2. Issue non-zero speed command to start the motor (refer to Section 2.4, step 1 on how to issue non-zero speed command). Motor will spin in open loop.
  3. Allow the open loop current to settle down and then measure the peak open loop current.
  4. Stop the motor and set the control mode [CTRL_MODE] to current control.
  5. Slowly increase the speed command until the motor speed reaches the max speed. Note down the Iq_ref value being reported in the IQ_REF_CLOSED_LOOP register.
  6. Speed loop Kp [SPD_LOOP_KP] is calculated using:
    Equation 2. S p e e d   l o o p   K p   =   I q   r e f e r e n c e   a t   m a x i m u m   s p e e d M a x i m u m   E l e c t r i c a l   S p e e d   i n   H z  
  7. Speed loop Ki [SPD_LOOP_KI] is calculated using:
    Equation 3. S p e e d   l o o p   K i = 0.1   × S p e e d   l o o p   K p
  8. Stop the motor and set the control mode [CTRL_MODE] to speed control.
Note: Tuning speed loop Kp and Ki is experimental. If the above recommendation doesn’t work, then we recommend to manually tune Speed loop Kp and Ki till the desired results are achieved.