SLLA665 April   2025 MCF8315A , MCF8315C , MCF8315C-Q1 , MCF8315D , MCF8316A , MCF8316C-Q1 , MCF8316D , MCF8329A , MCF8329A-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Open Loop and Handoff Stage
  5. 2EEPROM Configurations Affecting Open Loop to Closed Loop Handoff
  6. 3Open Loop to Closed Loop Handoff Tuning
    1. 3.1 Experimental Way to Tune Open Loop and Handoff Stage
      1. 3.1.1 Step-1: Initial Configuration
      2. 3.1.2 Step-2: Tuning of Parameters In Case Handoff is not Proper
        1. 3.1.2.1 Tuning of OL_ILIMIT
        2. 3.1.2.2 Tuning of Open Loop Acceleration Co-Efficient A1
        3. 3.1.2.3 Tuning of Handoff Thresholds
      3. 3.1.3 Step-3: Tuning of Handoff Configurations
  7. 4Optimum Handoff
    1. 4.1 Open Loop Time With the Recommended Settings
    2. 4.2 Open Loop Time by Following Optimum Handoff Steps
  8. 5Summary
  9. 6References

2 EEPROM Configurations Affecting Open Loop to Closed Loop Handoff

Table 2-1 Parameters Affecting Open Loop to Closed Loop Handoff
Sl. No Config Parameter Description
1 OL_ILIMIT Open Loop Current Limit
2 OL_ACC_A1 Open loop Acceleration coefficient A1 (in Hz/sec)
3 OL_ACC_A2 Open loop Acceleration coefficients A2 (in Hz/sec^2)
4 OPN_CL_HANDOFF_THR

Open loop to closed loop handoff threshold (% of MAX_SPEED).

Speed at which handoff happens if AUTO_HANDOFF_EN = 0h.
5 AUTO_HANDOFF_MIN_BEMF Minimum BEMF required before handoff. Handoff speed depends on motor back emf, if AUTO_HANDOFF_EN = 1h
6 THETA_ERROR_RAMP_RATE Ramp rate for reducing theta error (difference between open loop theta and estimated theta) linearly after handoff.
8 CL_SLOW_ACC Closed loop acceleration rate while theta error is non-zero.
Note: TI recommends OL_ILIMIT_CONFIG to be set to 0b, if the bit-field is available for configuration in the selected device.