TPS61071-Q1: Can that device output negative voltage on the SW pin ?

Ohad Fundoianu

Part Number: TPS61071-Q1

Hello,

I need a boost converter for up converting 2.9v or 3.3v to +3.5v and -3.5v. I found in TI web-site the TPS61071 Boost converter.

In the beginning of its Datasheet it says that in its typical application it converts only to positive output.

However, I looked over the datasheet and found that it has another application connectivity which was called "Power supply solution with auxilliary negative output voltage" as in the figure above.

I would like to understand, since it wasn't explained clearly in the datasheet, what is that mean ?

Does it mean this device can output positive and negative voltages in the same time from the VOUT (positive) and SW (negative) pins ? If it does than what is the supplied current on each power pin in such a case ?

Thanks,

Ohad F - Philips

over 4 years ago

0 Minqiu Xie over 4 years ago

TI__Mastermind 21565 points

Hi Ohad:
That's a usage like boost plus a charge pump. And it could supply for a negative Vout. The positive output is VCC, and negative output is VCC2.

Is you use if for amplifier? May you share some details about your application. So that I may help to check if it's suitable for you.

0 Ohad Fundoianu over 4 years ago in reply to Minqiu Xie

Intellectual 540 points

Hi Minqiu,

The application I want to use it in is for supply positive voltage and negative voltage for an ASIC which its current consumption on each of these rails is :

Positive voltage : 3.5v/100mA

Negative voltge: -3.5v/100mA

0 Minqiu Xie over 4 years ago in reply to Ohad Fundoianu

TI__Mastermind 21565 points

Hi Ohad:
It seems could work, but I afraid the -3.5V may not so precise. As this circuit only able to regulate one channel.

I'll recommend you to have a try in bench. And to check if it could meet your requirement. If not, we may need another part.

0 Ohad Fundoianu over 4 years ago in reply to Minqiu Xie

Intellectual 540 points

OK,
So to use the same device for negative output voltage only ? or shall I use other device for negative output ?
(-1.9 to -3.5)

0 Minqiu Xie over 4 years ago in reply to Ohad Fundoianu

TI__Mastermind 21565 points

Hi Ohad:
It's not recommended to use it for negative output voltage only. You may check if there is a charge pump could meet your requirement.
www.ti.com/.../overview.html

0 Minqiu Xie over 4 years ago in reply to Minqiu Xie

TI__Mastermind 21565 points

Hi Ohad:
I closed the thread assuming that you had solved the issue. if not, just reply below. Thank you.

Power management

Power management forum

TPS61071-Q1: Can that device output negative voltage on the SW pin ?