Hi TI team,
We use DRV8912-Q1EVM to connect the three-way valve for load test. One end of the three-way valve is connected to OUT4/6/7/9 and the other end is connected to OUT3/10/11/12. During the process of controlling the positive and negative rotation of the load, some OUT terminals will report overcurrent or OLD faults, and the fault OUT port is uncertain. What might be the cause of this problem? Is there any way to avoid this problem? Many thanks!
Hi
Thank you for your questions. Let me suggest followings.
1) As first step, I suggest to check status registers then figure out which channel has fault condition.
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2) Based on your description, you have both OCP and OLD fault. Please disable OLD function by OLD_CTRLx register for further debug of OCP.
Now I suggest to monitor the nFAULT pin and OUTx (voltage and current)with oscilloscope. Then single trigger with nFAULT (High->Low) signal. It should have high peak current on OUTx when nFAULT toggle to low. Peak current could be more than 1.3A. Need to contain this peak to avoid OCP.
If it is short period of rush current, adjusting OCP_DEG may help.
3) After resolving OCP, I suggest to back to OLD. Basically OLD is detected if motor current is lower than a certain level while driving. OLD can be disabled if not needed.
For further details, please refer 8.3.3.5 Open-load detection in datasheet if OLD function will be used.
regards
Shinya Morita
