TPS62912: Generate a negative output from +12V input

Thomas Sørensen

Prodigy 60 points

Part Number: TPS62912
Other Parts Discussed in Thread: TPS62913

Tool/software:

Hi,

Quick question.

Is it possible to generate a -1.8V from TPS62912 with a +12V input?

I was thinking to switch GND and VOUT on the output of the switch regulator.

Br.

9 months ago

+1 Lucia Gao 9 months ago

TI__Mastermind 25290 points

Hi Thomas,

Thanks for reaching out! Could you pls share me what is the -1.8V powered for? And what is your application/end equipment and project volume?

We have User's guide discuss about TPS62913 IBB design: TPS62913 Inverting Buck Boost EVM User Guide

Thanks!

BRs

Lucia

0 Thomas Sørensen 9 months ago in reply to Lucia Gao

Prodigy 60 points

Hi Lucia,

Thank you for the answer.

Exactly what I was looking for.

The -1.8V is used only for some opamps and some other very low current usage ICs.

Regarding your other questions, I would like to answer in private.

Br. Thomas

0 Thomas Sørensen 9 months ago in reply to Thomas Sørensen

Prodigy 60 points

Hi Lucia,

I have a follow up question. In the note you send, it mention that it is necessary to have a negative voltage to enable and disable the device, since the ENABLE is now referenced to the negative VOUT. I understand that a negative voltage is required to disable the device which should be 0.9V below VOUT, which is now negative.

But to enable the device, that should just require that the enable voltage is 1V above VOUT.

In my case with 12V as input I see this as I will always have it ON an cannot turn it off, unless I use a circuit as shown in the note?

Br. Thomas

0 Lucia Gao 9 months ago in reply to Thomas Sørensen

TI__Mastermind 25290 points

Hi Thomas,

Correct. You cannot turn it off if without any special circuit even if VIN is below UVLO.

Thanks!

BRs

Lucia

Power management

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TPS62912: Generate a negative output from +12V input