TPS65265: Using Triple output regulator for inductive and electronics loads

Hardik Godara

Prodigy 140 points

Part Number: TPS65265

Hello,

I intend to use TPS65265 in the following configuration:

Buck1: 5V@4A: For Motors

Buck2: 3.3V@1.5A: For LED drivers

Buck3: 3.3V@1A: For uC and controller circuitry

Input Voltage: 7-12V DC

I wanted to know if there would be any power dissipation or heating issues with this configuration. And if so, is there any heat sink recommendation for the same?

Also I hope this PMIC can handle the above power output in this configuration.

For the PSM/FCC mode, if I select PSM mode operation, does it mean that in higher load conditions the device still operates in PSM mode or will it switch to FCC mode when the current goes above certain threshold?

Thanks.

over 6 years ago

0 Edwin Zang over 6 years ago

TI__Expert 6425 points

Hi Godara,
1, we need to check the temp on EVM board in the configuration. And we will give you answer as we got the result.
2, in PSM mode, when loading is light, IC works with skip frequency, once loading is above certain threshold, it works with normal frequency. so light loading efficiency is higher.
in FCCM mode, although loading is very light, it couldn't skip frequency.

Best regards.

0 Hardik Godara over 6 years ago in reply to Edwin Zang

Prodigy 140 points

Hi Edwin,

Understood. Thanks for the prompt reply. I will wait for the results.

0 Zhao Ma over 6 years ago

TI__Genius 15135 points

Hi, Godara

Under your application, room temperature=25C.

Buck1: 5V@4A: For Motors

Buck2: 3.3V@1.5A: For LED drivers

Buck3: 3.3V@1A: For uC and controller circuitry

I measure the thermal as below, we can see the IC top case temperature is 66C under 25C room temperature. TPS65265 has good thermal performance under room temperature.

Confirm with you: What is the ambient temperature range in your application? is it -40C ~ 85C?

0 Hardik Godara over 6 years ago in reply to Zhao Ma

Prodigy 140 points

Hello Zhao,

The ambient temperature range will be ~5 to 45 C. So, the IC can handle this much power load and still doesn't heat much.

Thanks for the information. This answers my query.

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TPS65265: Using Triple output regulator for inductive and electronics loads