[SOLVED] TLE9879 BDRV Drain source problem

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User16336
Level 1
Level 1
Hi
I use TLE9879-EvalKit for sensorless BLDC motor. Application work perfectly, but i have one problem.
When motor in not running and all switches are off, i see short circuit on high side switches (see pic.1).
When motor is running (motor work perfectly), i see short circuit on all switches (see pic.2).
Disable drain source is not solve problem. What could be the problem? I think problem is BDRV settings, but i not find her.
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12 Replies
Lykaon
Employee
Employee
First like received
Hi Sanyxx,
could you please increase the dead time and try again?
Best regards
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User16336
Level 1
Level 1
Hi Lykaon
I tried. Old dead time was 1.5 uS, new 3.5 uS. But it not decided my problem.
In stop mode all mosfet are off. But status high side mosfets are "drain source detected".
If i disable one of high-side driver - all ok. But if all three high-side drivers are enabled - all high mosfets are drain source detected.
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Lykaon
Employee
Employee
First like received
Ok, understood.
What is your DS_Montitoring threshold?
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User16336
Level 1
Level 1
DS_Montitoring threshold is 0x3 (1V)
I attached screenshots all BDRV registers.
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Lykaon
Employee
Employee
First like received
Thanks for the pictures. Could you please capture SHx/GHx/GLx with an oscilloscope and post the picture here as well?
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User16336
Level 1
Level 1
Yellow - GL, Blue - SH, Pink - GH
SRC04 - zero position
SRC03 - stop motor condition (DS flags - all high side)
SRC01 & SRC02 - run motor condition (DS flags - all mosfet)
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Lykaon
Employee
Employee
First like received
Please measure the High-Side (Gate - Source) differentially. It looks like there is no sufficient DC-Link capacitance or your line impedances are too high -> deep voltage drop (CH3) to high-side gate on.
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User16336
Level 1
Level 1
I do not have equipment for directly measuring Vgs high side.
In previous oscilloscope (pic 3) you can see that in stopped mode Vgs of high side mosfets are zero. But DS flags setted.
I think that i not correct made BDRV settings. I may send you my project for evalkit and GUI in private and you will can saw that problem.
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Lykaon
Employee
Employee
First like received
Hi,
are you able to send the project via private message (forum)?
Best regards
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User16336
Level 1
Level 1
Pasword in private message
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User15455
Level 2
Level 2
10 sign-ins 5 sign-ins 10 replies posted
Could the HSx_OC_DIS be disabled?
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User15455
Level 2
Level 2
10 sign-ins 5 sign-ins 10 replies posted
About the DS_STS, i think it can be ignored during the DS-Current source diabled.

27.4.1.1.2 Detection
To return to normal operation, disable the DS-Current sources for each phase, the value of the DS-STS flags have to be ignored from now on
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