TPS54KC23: Ground shifting to adjust Vout

Sharat Chandra

Part Number: TPS54KC23

Tool/software:

Hi,

For our application, I think we can use this regulator. Our goal is to generate +/-5V.

I am thinking I can connect PGND = AGND = -12V, Vin = +12V

Would this work? My assumption :Rail levels are maintained and I should Vout-AGND levels = same as what it would be with PGND=AGND = 0V and Vin = 24V. Is this assumption correct?

Also, I notice in the user application that the there are two grounds shown in the block diagram. Can you please explain an example use case for the same?

6 months ago

0 Tomoya Ide 6 months ago

TI__Genius 11356 points

Hi Sharat,

Are you referring to using the TPS54KC23 in an inverting buck-boost topology, as described in this application note? https://www.ti.com/lit/ds/symlink/tps54kb20.pdf

If that's the case, the setup effectively involves converting 17V to 5V with the output connected to the system ground. However, please note that the device is only rated for 16V, making it unsuitable for this application.

I recommend looking for another similar device that can support an input voltage range of 17V or higher.

Thank you,
Tomoya

0 Sharat Chandra 6 months ago in reply to Tomoya Ide

TI__Prodigy 70 points

Hi Tomoya,

Firstly I am sorry but I did not find an inverting buck boost application note in the datasheet that you sent.

But more importantly, my question was slightly different.

What I would like to do is make PGND = AGND = -12 and Vin = 12V. For the regulator, all the conditions are met correct? Effective Vin-AGND = 24V.

Now relative to this, the absolute voltages of +/-2.5V should appear on the output correct?

I am wondering if this works or am I missing something here?

Regards,

Sharat

0 Calan Elaya 6 months ago in reply to Sharat Chandra

TI__Genius 11305 points

Hi Sharat,

Tomoya will respond to this in a few days.

Thanks,

Calan

0 Tomoya Ide 6 months ago in reply to Sharat Chandra

TI__Genius 11356 points

Hi Sharat,

My apologies, but I posted a link to the datasheet, not the app note. Here is the correct link for the app note:

https://www.ti.com/lit/an/slyt286/slyt286.pdf

The issue is the input voltage rating of the device is 18V ABS max, so it cannot support 24V Vin-AGND or Vin-PGND.

Thank you,
Tomoya

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TPS54KC23: Ground shifting to adjust Vout