Tool/software:
I created a circuit for driving a motor using the MCT8316Z0R (SPI). So far, it is working as intended.
To detect fault conditions, I would like to detect motor open circuit and hall sensor open circuit. I thought that all of these could be detected by the MCT8316Z's motor lock detection, but it was not able to detect them as I expected.
What I tried:
- One of the hall sensor connections was disconnected.
- The motor rotates unsteadily and rattles
- Since there is no torque and the motor shaft can be easily stopped by hand, I tried stopping it, but the MCT8316Z did not go into a fault state.
- All hall sensors were disconnected (motor drive was connected).
- The motor won't spin at all, but the fault won't activate either.
- If left as is, the MCT8316Z entered an OTF (Overtemperature) fault state.
- One of the motor drive wires was cut
- Even if the wire is cut while the motor is rotating, it may continue to rotate depending on the direction of rotation of the motor. (I don't think this is a problem
- When I stopped the motor and tried to start it again, it immediately went into a fault state (which was the expected behavior).
In the 1/2 state, no FGOUT pulse is output. The lock state can be determined by monitoring FGOUT using an external MCU, but I would like to detect the lock state as the MCT8316Z itself if possible.
What could be the problem? Or am I misunderstanding how the MCT8316Z motor lock detection works?
Condition:
- Supply voltage(Vvm): 24V
- PWM frequency: 20kHz
- Slew rate setting: 25V/us
- Back regurator output: 5.7V 600mA
- Mode: digital Hall input/ Synchronous modulation/ ASR,AAR disabled
- Lock detect: MTR_LOCK_TDET=2h(1,000ms), MTR_LOCK_MODE=0h (Motor lock causes a latched fault)
