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TPS610981: Understanding the difference between devices/IoT low-power regulation from 3.6V primary cell

Craig Easdale
Expert 2170 points
Part Number: TPS610981
Other Parts Discussed in Thread: CC1310, , TPS62740, TPS61291

I'm looking for a power solution for my ultra-low power IoT application based on the CC1310.

  • I'll be using a LiSOCl2 battery, so can expect an input voltage range of about 3.0 to 3.7V.
  • I am trying to get a consistent, efficient 3.3V output with about 100-200mA.
  • Since it's a low power/mostly sleep mode device I need a quiescent current < 2uA

I stumbled across the TPS610981 but I'm having a hard time distinguishing it from other parts in the same family. In the datasheet it has a device comparison table, but I'm struggling to understand what each column means.

Could someone explain to me the meaning of the columns in the table on page 3 (http://www.ti.com/lit/ds/symlink/tps62730.pdf)

Also, are there any other parts or combination of parts which may fit my regulation requirements?

  • 0
    TI__Mastermind 46905 points
    the TPS610981 is the right part for your application if you want to keep the CC device voltage not lower than 3.3V. i would suggest you to read the datasheet carefully, then you can understand the table. it is hard for me to explain this clearly in short sentence.
    however, i don't understand why you need to boost converter. i think the CC device can be connected to the battery directly.
    and this kind of battery can't support 200mA output current as i know.
  • 0 in reply to Jasper Li
    Expert 2170 points
    The cc1310 may be able to handle 3.7v, but other devices in the system cannot. I'd like to power everything from the same voltage rail for simplicity.

    I have read through the datasheet and I still don't quite understand how I can get a stable 3.3V out from a voltage ranging from 3-3.7V. Could you please explain?
  • 0 in reply to Craig Easdale
    TI__Mastermind 46905 points
    it is a boost device, it can't regulate 3.3V output if the input voltage is 3.7V. you need a buck converter to get 3.3V from 3.7V input.
  • 0 in reply to Jasper Li
    Expert 2170 points
    Okay, I have misunderstood the purpose of the device then. I thought it was an LDO until it dropped below 3V3 at which point it would operate in Boost mode.

    So with that probably ruled out as a part, are there any other appropriate TI regulator parts that would enable me to have a stable 3.3V from a 3-3.7V input range, while also having sub 2uA quiescent current?
  • 0 in reply to Craig Easdale
    TI__Guru**** 150900 points
    Since your 3.3Vout is between the high and low end of your battery voltage, you would ideally need a buck-boost converter. However, there is not such a low Iq one in the market today.

    You have a few options:
    Use a low Iq boost, followed by a low Iq buck (TPS62740).
    Raise or lower your desired 3.3Vout. This may involve using a different supply for the different pieces of your system.
    The TPS61291 is a boost + bypass converter, which operates in a very low Iq bypass mode and then switches to boost mode when the supply voltage is lower.