TPSM365R6: TPSM365R6

CHARAN RAJ

Part Number: TPSM365R6

Tool/software:

I am using the TPSM365R6V5RDNR module in my design. The input supply range is 48V nominal, with occasional peaks up to 60V.

I have observed that when the input voltage goes above 55V, the IC starts heating significantly compared to lower input levels.

My configuration is as follows:

Input Voltage Range: 48V nominal (tested up to 60V)
Output Voltage: 5V
Load Current: 0.1A
PCB Design: Followed recommended layout from datasheet

Please advise on how to mitigate this heating issue.

14 days ago

0 Niranjan Nair 14 days ago

TI__Genius 9760 points

Hi,

TPSM365R6V5RDNR is a fixed output variant of the device. You can connect FB directly to VOUT and remove R8, R5, C20 for 5V output.

This should reduce the power dissipation by a bit. Please try this out and let me know if it works.

Regards,

Niranjan

0 CHARAN RAJ 14 days ago in reply to Niranjan Nair

Prodigy 10 points

That was designed for both fixed and variable output IC's , currently im not mounting R8,R5 and C20.

0 Niranjan Nair 13 days ago in reply to CHARAN RAJ

TI__Genius 9760 points

Can you share the layout for review?

0 CHARAN RAJ 13 days ago in reply to Niranjan Nair

Prodigy 10 points

0 Niranjan Nair 13 days ago in reply to CHARAN RAJ

TI__Genius 9760 points

When you say significant heating, how hot does the case get? Do you have a thermal camera or something to measure the temperature?

It is expected that at higher Vin, the power dissipation and heating will be higher, but there is no reason for a significant jump above 55V Vin.

0 CHARAN RAJ 13 days ago in reply to Niranjan Nair

Prodigy 10 points

No, I don’t have a thermal camera. I checked physically, and it seems to be around above 50 °C. For the same supply and load, the EVK board is not heating.

0 Niranjan Nair 13 days ago in reply to CHARAN RAJ

TI__Genius 9760 points

The EVK board is usually designed for optimal efficiency and thermal performance with good heat sinking. If your board is more compact then it is expected to heat up more compared to the EVM.

That being said, 50C is not too high and is to be expected when such high step-down ratios are involved. If there are any specific application related concerns about that temperature, you might have to have a larger copper area.

As a side note (not related to the heating issue), I do have some comments about the board layout

1) The FB resistors should ideally be placed close to the FB pin on the same layer.

2) I am not able to see the input ceramic cap C5 in the picture. It should be placed as close as possible to the VIN pin and on the same layer

3) VCC cap C18 should also be close to VCC pin and on the same layer

These are mainly to have better noise performance at the respective pins

0 CHARAN RAJ 11 days ago in reply to Niranjan Nair

Prodigy 10 points

We will do more experiment and get back to you.

0 Niranjan Nair 11 days ago in reply to CHARAN RAJ

TI__Genius 9760 points

Sure, let me know if you face any issues

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TPSM365R6: TPSM365R6