TPS61391: TPS61391 without using the current mirror

Ronald Rehfinger

Part Number: TPS61391

Hello Support,

I want to use the TPS61391 without the current monitor, I just need a boost converter. I learned from another thread that I can leave the current mirror pins (AVCC, CAP, APD, MONIN, MON1, MON2) open when the current mirror is not used. Judging from the Block Diagram the could also be the case for ISHORT. Can you confirm that?

But when I do a design in the Webench Power Designer, I have the option to disable the current mirror, and the schematics has still components on all the current mirror pins. Are these component actually needed? I'm confused, who is right, the Webench or the forums?

Regards

over 5 years ago

0 Helen chen over 5 years ago

TI__Mastermind 40080 points

Dear Sir,

Thanks for the post. Yes, the TPS61391 can be used as a pure boost converter.

Please check the attached schematic. By the way, what is your Vin, Vout and Iout in your application?

0 Helen chen over 5 years ago in reply to Helen chen

TI__Mastermind 40080 points

Sorry, I missed the schematic. TP61391 pure Boost.pdf

0 Ronald Rehfinger over 5 years ago in reply to Helen chen

Intellectual 320 points

Hi Helen,

I see no schematics attached. Can you please repost it? Got it!

Vin: 3.3V - 5V, Vout = 60V, Iout = 20mA

Regards

0 Helen chen over 5 years ago in reply to Ronald Rehfinger

TI__Mastermind 40080 points

Dear Sir,

Got it.

When Vin>=4V, the TPS61391 has Vout = 60V, Iout = 20mA output capability.

When Vin=3.3V, the maximum output current at Vo=60V is around 15mA.

0 Ronald Rehfinger over 5 years ago in reply to Helen chen

Intellectual 320 points

Hi Helen,

the schematics is really helpful and looks more plausible than leaving all pins pins floating. Thanks!

But in your schematics pin 1 is labeled as AVCC whereas the datasheet defines it as NC:

TPS61391 RTE_wqfn-162_SLVSFE7.gif

Is this an error in your schematics symbol, or in the datasheet...?

Regards

0 Helen chen over 5 years ago in reply to Ronald Rehfinger

TI__Mastermind 40080 points

Dear Sir,

Very good finding.

You can follow the datasheet. But the schematic I send to you is also OK. Pin 1 can be either connects to AVCC or GND.

The mismatch is due to the datasheet change.

0 Ronald Rehfinger over 5 years ago in reply to Helen chen

Intellectual 320 points

Hi Helen,

I understand, thanks a lot.

When the datasheet should be updated, I suggest an additional chapter on how to use the TPS6139x as a pure boost converter. The device now seems to be quite simple to use as boost converter, so this could be a valuable addition.

Regards

0 Helen chen over 5 years ago in reply to Ronald Rehfinger

TI__Mastermind 40080 points

Very good suggestion. I will forward your suggestion to the datasheet writer.

Good Luck ! :)

Power management

Power management forum

TPS61391: TPS61391 without using the current mirror