TPS61089: TPS61089 circuit question.

fangxing sun

Intellectual 310 points

Part Number: TPS61089

Dear sir

Our project wants to select TPS61089. Our requirement is Vin = 2-3V Vout = 6.5V Iout=1.5A.

But TPS61089 Vin minimum requirement is 2.7V. So I prepare use 3.3V to supply Vin. Vbat connects to power inductor L1.

Please help me check like this using method is OK or not. Thanks very much.

over 7 years ago

0 Helen chen over 7 years ago

TI__Mastermind 40080 points

The conneciton is OK. TPS61089 supports this kind of usage!

0 fangxing sun over 7 years ago in reply to Helen chen

Intellectual 310 points

Thanks for your reply.

How to understand Iq characterize. I check spec Iq Vin=3uA, Vout=180uA. It means total Iq=183uA.

My understand is correct?

our project needs very lower quiescent current. So how to reduce TPS61089 Iq performance.

Thanks.

0 Helen chen over 7 years ago in reply to fangxing sun

TI__Mastermind 40080 points

Yes, your understanding is right!

Generally, bigger output power capabilty IC has bigger Iq. What is your Vin, Vo, Io?

0 fangxing sun over 7 years ago in reply to Helen chen

Intellectual 310 points

Dear helen

Vin from 2V to 3V, Vo is 6.5V Io is 1.5A.
How about Iq in PFM mode. I think it can reduce Iq?
Iq test result is PWM mode or PFM mode?

0 Helen chen over 7 years ago in reply to fangxing sun

TI__Mastermind 40080 points

The Iq is tested under the no switching condition. what kind of current you need, it seems you need no load current, right?

0 fangxing sun over 7 years ago in reply to Helen chen

Intellectual 310 points

Dear helen

This boost IC use for boost back battery power remains system working when main battery disconnect.
After 1 min software will shutdown all function into deep sleep mode, only a MCU working. Because our back battery is the non-charge type. So we need low Iq in the system shutdown.
Before software entire deep sleep, our system power consumption is 10W.

0 fangxing sun over 7 years ago in reply to Helen chen

Intellectual 310 points

Dear helen

Base on our requirement. Did you have another better choice to advice?
Thanks

0 Helen chen over 7 years ago in reply to fangxing sun

TI__Mastermind 40080 points

Do you mean after 1min, the TPS61089 need to supply the MCU only? Or is the MCU supplied by the back battery? Then for the TPS61089, there's no load at all?

0 fangxing sun over 7 years ago in reply to Helen chen

Intellectual 310 points

Yes， your understanding is correct. This time tps61089 near no load status.

0 Helen chen over 7 years ago in reply to fangxing sun

TI__Mastermind 40080 points

when TPS61089 works in the no load condition, it works in the PFM mode, the noload input current is less than 1mA.

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TPS61089: TPS61089 circuit question.