MCT8329EVM: GVDD

PRABHAT RANJAN TRIPATHI

Part Number: MCT8329EVM
Other Parts Discussed in Thread: MCT8329A, CSD19534Q5A, CSD18536KTT

Tool/software:

I am getting a GVDD_UV_Fault.

I checked the GVDD pin, I have connected a 4S battery pack with current voltage at PVDD as 16 Volts, I am able to connect the MCT8329EVM and read and write the registers.

Initially the voltage at GVDD is 13 Volt but as soon as I give speed command through I2C, the GVDD goes to zero and GVDD_UV_Fault is triggered.

over 1 year ago

0 PRABHAT RANJAN TRIPATHI over 1 year ago

Expert 1102 points

And it gets clear from the GUI when the speed command is zero

0 Anthony Lodi over 1 year ago in reply to PRABHAT RANJAN TRIPATHI

TI__Mastermind 26826 points

Hi Prabhat,

Today is a Holiday in the US, we will aim to provide a response by the end of the week.

Regards,

Anthony

0 Joshua Horlander Cruz over 1 year ago in reply to PRABHAT RANJAN TRIPATHI

TI__Mastermind 24860 points

Hi Prabhat,

Can you provide a capture of PVDD, CPH, GVDD, and BSTA when a speed command is given?

Regards,

Joshua

0 PRABHAT RANJAN TRIPATHI over 1 year ago in reply to Joshua Horlander Cruz

Expert 1102 points

PLease find attached the screenshots

Capture.zip

0 Joshua Horlander Cruz over 1 year ago in reply to PRABHAT RANJAN TRIPATHI

TI__Mastermind 24860 points

Hi Prabhat,

How many MCT8329A units are experiencing this issue?
Have you made any modifications to the MCT8329EVM you are using?
It seems like there maybe a short somewhere on the gate driver side of the device. Can you measure the resistance between the following pins to see if there is a short?
1. GLA and LSS
2. GLB and LSS
3. GLC and LSS
4. GHA and SHA
5. GHB and SHB
6. GHC and SHC
7. Drain to Source of each low side MOSFET

Regards,

Joshua

0 PRABHAT RANJAN TRIPATHI over 1 year ago in reply to Joshua Horlander Cruz

Expert 1102 points

Yes MOSFETs of the leg B were faulty.

Can I change those MOSFETs, I don't have exact part replacement, but can I use

CSD19534Q5A

instead?

0 PRABHAT RANJAN TRIPATHI over 1 year ago in reply to PRABHAT RANJAN TRIPATHI

Expert 1102 points

IRFS7530TRL7PP

0 Joshua Horlander Cruz over 1 year ago in reply to PRABHAT RANJAN TRIPATHI

TI__Mastermind 24860 points

Hi Prabhat,

Both of the MOSFETs have a different package than the CSD18536KTT MOSFET which has a TO-263 package and they likely will not be able to be placed on the board where the CSD18536KTT was. If either of these MOSFETs do fit, then they can be used in place of the CSD18536KTT on the board.

If you use a different MOSFET, I would recommend replacing all of the MOSFETs if you change one of them to a different MOSFET.

You can look for MOSFETs with the same package here: https://www.ti.com/power-management/mosfets/products.html#1241=N-channel&2954=TO-263&.

To make the half bridge design more robust, please consider adding gate resistors and/or RC-snubbers. The footprints for the components required to implement these are already on the MCT8329EVM.

Regards,

Joshua

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MCT8329EVM: GVDD