SLVAFF1 January   2023 DRV8452 , DRV8462

PRODUCTION DATA  

  1.   Abstract
  2.   Trademarks
  3. 1Power Efficiency of Stepper Motor Drivers
  4. 2Auto-Torque
    1. 2.1 Auto-Torque: Learning Principle
      1. 2.1.1 Configuring Auto-Torque Learning Routine
    2. 2.2 Current Control
      1. 2.2.1 Setting Current Control Parameters
    3. 2.3 PD Control Loop
    4. 2.4 Impact of Auto-Torque Tuning Parameters
      1. 2.4.1 Impact of Learning Parameters on Load Transient Response
      2. 2.4.2 Impact of ATQ_UL, ATQ_LL Hysteresis
      3. 2.4.3 Impact of Load Profile on Power Saving
      4. 2.4.4 Adaptive ATQ_UL, ATQ_LL
      5. 2.4.5 PD Parameter Dependency Curves
        1. 2.4.5.1 Dependency on KP
        2. 2.4.5.2 Dependency on KD and ATQ_D_THR
        3. 2.4.5.3 Dependency on ATQ_FRZ and ATQ_AVG
        4. 2.4.5.4 Dependency on ATQ_ERROR_TRUNCATE
      6. 2.4.6 ATQ_CNT at Different Motor Speeds
      7. 2.4.7 ATQ_CNT at Different Supply Voltages
      8. 2.4.8 Motor Temperature Estimation
    5. 2.5 Efficiency Improvement With Auto-Torque
  5. 3Case Studies
    1. 3.1 Application 1: ATM Machines
      1. 3.1.1 ATM Motor Operating Conditions
      2. 3.1.2 ATM Motor With Auto-Torque
    2. 3.2 Application 2: Textile Machines
      1. 3.2.1 Textile Motor Operating Conditions
      2. 3.2.2 Textile Motor With Auto-Torque
    3. 3.3 Application 3: Printer
      1. 3.3.1 Printer Motor With Auto-Torque
  6. 4Summary
  7. 5References

2.4.2 Impact of ATQ_UL, ATQ_LL Hysteresis

If the hysteresis band between ATQ_UL and ATQ_LL is widened by increasing the difference, it improves the immunity of the algorithm against system noise.

  • As shown in Figure 2-12, smaller hystsresis means the response to load increase or decrease is similar.
  • Figure 2-13 shows that larger hysteresis causes the current take longer time to reduce when load is reducing, leading to slower response to decreasing load, and slightly poorer efficiency. But it helps in situations where the load has noisy transients.
GUID-20221117-SS0I-CXVX-13KR-GL8VPJVTZTJR-low.pngFigure 2-12 ATQ_UL = 40, ATQ_LL = 40
GUID-20221117-SS0I-2GBP-SGMB-73DTVD2K2PJC-low.pngFigure 2-13 ATQ_UL = 40, ATQ_LL = 20