DRV8161EVM: Thermal Via: tented or untended

Darshankumar Pandit

Part Number: DRV8161EVM
Other Parts Discussed in Thread: CSD19536KTT, DRV8161, DRV8162

Tool/software:

Hi,

We are taking DRV8161EVM to production for 2 wheeler electric vehicle application.

We wish to scale the design from 30A to 150A peak currents (for 2 mins) & nominal currents of 50A. The current sense & other updates are completed and functional design is okay.

Present design query is related to thermal design with the above changes:

Following are the queries:

Let us know if thermal vias used for CSD19536KTT in DRV8161 should be tented or untented. (Some images are attached for reference)
let us know maximum copper layer thickness we can achieve in this design.
Let us know recommended spacing between tracks & track width for increasing the Finish Copper layer thickness to 140μ/4 oz & Inner Copper layer thickness to 70 μ/2 oz

Let us also know if there are additional reference design using CSD19536KTT & DRV8161EVM with higher currents that we can refer to.

Have a good day.

7 days ago

+1 Akshay Rajeev Menon 7 days ago

TI__Mastermind 23546 points

Hey Darshankumar,

Darshankumar Pandit said:
Let us know if thermal vias used for CSD19536KTT in DRV8161 should be tented or untented. (Some images are attached for reference)

In our Evaluation module we use tented vias.

Darshankumar Pandit said:
let us know maximum copper layer thickness we can achieve in this design.

Maximum copper allowed would be dtermined by your PCB manufacturer. For higher current you will need wider copper pour and sitching it across multiple layers to dissipate the power to not violate the themal limits of the parts. You will need thermal simulation for more accurate numbers.

Darshankumar Pandit said:
Let us know recommended spacing between tracks & track width for increasing the Finish Copper layer thickness to 140μ/4 oz & Inner Copper layer thickness to 70 μ/2 oz

I would ask this to the PCB manufacturer.

I will loop in the MOSFET team for additional comments.

The following reference design with DRV8162 (very similar part) is the highest power one we have tested.(85A RMS, 48V)

https://www.ti.com/tool/TIDA-010956

Best,

Akshay

0 John Wallace1 7 days ago in reply to Akshay Rajeev Menon

TI__Mastermind 38300 points

Hello Darshankumar,

I don't have much more to add to Akshay's comments. I'm including a link to an app note with best practices for motor drive PCB layout below. There are a number of TI reference designs using the CSD19536KTT that can be found at the second link below. Please let us know if you have any additional questions.

https://www.ti.com/lit/an/slva959b/slva959b.pdf

https://www.ti.com/reference-designs/index.html#search?keyword=CSD19536KTT

Best Regards,

John Wallace

TI FET Applications

Motor drivers

Motor drivers forum

DRV8161EVM: Thermal Via: tented or untended