TPS552882-Q1: Power dissipation calculation

Elbin Thomas

Part Number: TPS552882-Q1
Other Parts Discussed in Thread: TPS55288

How to calculate the dissipation on TPS552882QRPMRQ1 IC and the two external N channel Mosfets for the following use case

1) Input 8V/24V and Output 12V @7.5A

When estimating dissipation based on efficiency, the calculated loss is around 10 W, which seems quite high.

Clarification is needed on whether this value is realistic and if the device can reliably operate at an ambient temperature of 85 °C under these conditions.

Thanks

2 months ago

0 Bryce Xun 2 months ago

TI__Mastermind 29120 points

Hi Elbin,

The expert will reply to you tomorrow, thanks for reaching out.

BRs,

Bryce

0 Elbin Thomas 2 months ago in reply to Bryce Xun

Prodigy 20 points

Hi Bryce Xun ,

Thanks for the update. I’ll wait for the response tomorrow.

Regards,

Elbin

+1 Colin Chen 2 months ago in reply to Elbin Thomas

TI__Mastermind 22431 points

Hi Elbin,

10W is a very exaggerating value for power dissipation. Please use the calculation tools to estimate:

https://www.ti.com/tool/download/SLVRBF9

From the result, it can be seen that power dissipation is about 2W and temp rise is about 81.4C. Because of thermal shutdown is 175C, it can work but very easy to meet thermal shut down.

0 Elbin Thomas 2 months ago in reply to Colin Chen

Prodigy 20 points

Hi Colin Chen ,

Thanks for the reply.

In the case of the TPS55288 operating in boost mode, most of the power loss should occur within the IC. Based on the efficiency (94.2%), I calculated around 5.5 W of power dissipation, but the TI calculator shows only about 2.2 W.

Could you please help explain what additional parameters or loss components I might be missing in my manual calculation?

0 Colin Chen 2 months ago in reply to Elbin Thomas

TI__Mastermind 22431 points

Hi Elbin,

Please refer to TI calculator.

Thanks,

Colin

0 Elbin Thomas 2 months ago in reply to Colin Chen

Prodigy 20 points

Hi Colin Chen ,

Thanks for the support

Regards,

Elbin

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TPS552882-Q1: Power dissipation calculation