TPS61291: Application Inquiry

Renan Santos Adriano

Part Number: TPS61291

Hello Team,

My customer would like to operate this in constant boost mode. The boost chip is configured for a 3.0V output but the input voltage will be about 3.2V until it drains down below 3.0V. The converter operates cleanly when the input voltage is less than 3.0V but has about 135mV of ripple when they bring the input voltage up to 3.2V. We would like to know if this is normal and we can reliably operate this part this way.

And in this configuration, when the input voltage is > 3.0V, the output doesn't track the input voltage. It does rise above 3.0V to about 3.15V.

Thanks in advance

Regards
Renan

over 3 years ago

0 Zack Liu over 3 years ago

TI__Mastermind 34221 points

Hi Renan,

When the device is disabled (EN/BYP = low), bypass mode is activated and internal P-channel MOSFET is turned on. Does customer configure the EN/BYP pin correctly?

0 Wenhao Wu over 3 years ago

TI__Genius 9046 points

Hi Renan,

Thanks for reaching out. Would they are able to manually program EN to be low to enter bypass mode? For if device can work in boost mode, I will need to check it out on bench after come back from CNY holiday.

Note I will be in time bank of Chinese New Year until 7th Feb.

-Wenhao

0 Wenhao Wu over 3 years ago in reply to Wenhao Wu

TI__Genius 9046 points

Hi Renan,

You can check below E2E thread for Vin>Vout behavior of TPS61291. It is a boost converter. If customer would like to use Vin>Vout, they must toggle EN/BYP low to enable bypass mode.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/667054/tps61291-about-boost-mode-on-high-vin-condition

-Wenhao

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TPS61291: Application Inquiry