MCF8315A: Support Request for BLDC Motor Control Using MCF8315A and Faulhaber 1628T024B

Tool/software:

Dear Support Team,

We have designed a controller using the MCF8315A driver to control the 1628T024B motor (datasheet: www.faulhaber.com/.../EN_1628_B_FMM.pdf).

The application requires:

• Using an MCU to control the speed, direction, and braking of the MCF8315A.
  
• Very fast speed response
• Braking functionality
• Forward/reverse direction control after each braking event
• Limited motor rotation angle of 180°
• Operating cycle: brake → rotate left 30° → brake → rotate right 30° → brake.

Current Register Configuration (MCF8315A):

ISD_CONFIG 0x00000080 0x6C720C20

REV_DRIVE_CONFIG 0x00000082 0x28200000

MOTOR_STARTUP1 0x00000084 0x036607D0

MOTOR_STARTUP2 0x00000086 0x1B06600C

CLOSED_LOOP1 0x00000088 0x0D3201BD

CLOSED_LOOP2 0x0000008A 0xABA5DD57

CLOSED_LOOP3 0x0000008C 0x24800005

CLOSED_LOOP4 0x0000008E 0x55F544CD

FAULT_CONFIG1 0x00000090 0x1A246146

FAULT_CONFIG2 0x00000092 0xF0D40888

PIN_CONFIG 0x000000A4 0x00000000

DEVICE_CONFIG1 0x000000A6 0x00000000

DEVICE_CONFIG2 0x000000A8 0x00000B000

PERI_CONFIG1 0x000000AA 0xC1C01F00

GD_CONFIG1 0x000000AC 0x9C450100

GD_CONFIG2 0x000000AE 0x80200000

ALGO_CTRL1 0x000000EA 0x00000000

INT_ALGO_1 0x000000A0 0xA433407D

INT_ALGO_2 0x000000A2 0x000001A7

We are currently facing several issues that we would greatly appreciate your support with:

1. With the current configuration, after each braking event the motor restarts very slowly, draws high current, and sometimes spins at an uncontrolled speed or fails to restart.
2. Controller_Fault_Status register continuously reports faults including CONTROLLER_FAULT, ABN_BEMF, MTR_LCK, and HW_LOCK_LIMIT.
3. We customized the brake pin to use align brake at the last commutation angle; however, this results in very high current consumption and causes the motor to overheat.

Therefore, we kindly request your support with the following issues:

1. Ensure the motor can start successfully, even without entering closed loop, since the rotation angle is relatively small.
2. Adjust the motor configuration to achieve the fastest possible startup and ensure correct rotation direction according to the DIR pin.
3. Resolve the faults reported in the Controller_Fault_Status register as mentioned above.
4. Is it possible to use align brake at the last commutation to achieve faster braking while allowing the current to gradually decrease after braking to avoid motor overheating, and still ensure that once the brake is released the motor can respond quickly to direction and speed commands?

Our project is currently behind schedule, and we would greatly appreciate your support.

We greatly appreciate your support and look forward to your feedback.