TPS7A94: PMIC or Discrete regulators

Part Number: TPS7A94
Other Parts Discussed in Thread: TPS7A14, TPS7A53B

Hi, I have a board I'm working on that requires the following power rails:

19V @ 2A

5V @ 3A

3V3 @ 1A

1V05 @ 1A

I'm trying to figure out whether I should be using 4 discrete regulators or a PMIC solution. At which point is it worth it to switch to a PMIC? I'm initially looking at the PMIC option because board space is a little tight, but I would rather not burden the SW team with additional work if I can avoid it. Is a PMIC worth it for this kind of situation, and could anyone recommend one to me that doesn't require much (or hopefully any) SW set up?

Thanks,

Matt

  • Hi Matt,

    My first thought is that power dissipation of the PMIC will be felt across each power supply.  You will want additional work placed into the thermal dissipation to ensure that power loss of each supply does not drive up the overall temperature of the PMIC.  I'm sending this to one of our engineers in the PMIC group for additional feedback.

    There are small 1A LDO's that may work for you.  The TPS7A14 may be an option for your 1.05V and 3.3V rail.  The TPS7A53B is a small 3A LDO and may be an option for your 5V rail.  If you need a very small converter for the 19V rail then we may need to look at TI switching converters unless you need an LDO.

    Thanks,

    Stephen

  • Thanks Stephen. I appreciate the feedback. I forgot to mention that the input power for this board is 24VDC, so I was planning on using switchers for the 19V and 5V supplies for power efficiency reasons. The issue is just that having 2 or 3 switchers and and LDO or 2 seems like it probably will take up more space than a single PMIC, though to your point, power density and heat generation may be higher with the PMIC. I would be interested to see what kind of heat management would be required.

  • Hi Matt,

    I am not sure if there is a PMIC in our portfolio that meets all of your requirements (higher voltage VIN and 19V output rail and small solution size). This PMIC product page can help you filter and look at the available options: https://www.ti.com/power-management/multi-channel-ics-pmic/products.html 

    Best regards,

    Matt