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PMIC for my application

Abhishek Sharma53
Prodigy 240 points
Other Parts Discussed in Thread: TPS65010, LP3910

Hi ,

I am looking for a Power management IC which can charge a 1C Li Ion/Polymer battery. This IC should receive 3.3V or 5V as regulated input and should give a 3.3V  300mA as output.

This output 3.3v should be driven through the input when input power is present and in absence of it , it should drive from the Li battery.

Please suggest a reference IC part number with an application note.

Thanks

Abhishek

  • 0
    TI__Mastermind 25800 points
    Heye Abhishek,

    Looking through our portfolio, I found a few options you can consider, but I may need more information to find a total solution.

    First off, said you said 1C charging, but what is the actual charge current or battery capacity you are looking to charge?

    Secondly, your output is 3.3V @ 300mA. Is this a constant 300mA or peak load current?

    Third, is which input will be active most of the time? 3.3V or 5V?

    Lastly, you may be hard pressed to find a charger that can still charge the battery when it's input is <4V. If your input is 3.3V, can you accept a non-charing condition?

    With that, I suggest you look into these PMICs we have available

    1) TPS65010/11/12/13/14 - These will have a limitation on the input voltage when it comes to charging (i.e. VIN < 4.5V)

    2) TPS6572x - Similar to the previous solution, and if you can get away with 200mA continuous current, it could work for your application.

    3) LP3910 - A very good solution for what you are looking for because it includes a buck-boost converter which helps for the 3.3V input, but you will run into the same issue for battery charging with that input source (VIN must be at least 4.25V (typical))

    Please note, most of these may be overkill if all you are looking for is the charger and the single output.

    You may want to consider a three/four IC discrete solution using a single-cell/multi-cell charger (depending on your battery spec), an input boost converter, and an output buck-boost converter.


    Hope this helps!

    Regards,
    Joel H
  • 0 in reply to Joel Hernandez II
    Prodigy 240 points

    Hi Joel,

    Thanks for the suggestions,were more knowledgeable . But are costly and complex solutions to my application.

    By now I have more clarity on what my requirements are

    1) I am targeting a coin cell Li-Ion battery something like RJD2450 Illinois Capacitor make battery  for a reference. (its not 1A as in my previous post, sorry for that)

      Battery capacity is 200mAH, charge rate is 0.5CA (  100mA) 

    2) 300mA is the peak load current

    3) As you exlpained  in your post, I would prefer the charging IC to be fed with 5 V. 

    So I will be really happy if you can suggest a solution which serves as battery charging operation as well as an LDO . Which means I give 5 V to this system and I receive a 3.3 V from it , when 5 V is present it charges the battery and also gives a 3.3V power fetching from the input and when 5 V is not present it gives 3.3V fetching power from the battery.

    Thanks

    Abhishek

  • 0 in reply to Abhishek Sharma53
    TI__Mastermind 25800 points

    Hey Abishek, 

    Based on the requirements above, I would suggest looking at the bq2512x family of parts. This part lets you set the system output voltage to 3.3V(max). The one condition you will want to be mindful of for this part, and like any other charger IC, is a battery only mode where typically the system voltage will match the voltage of the battery (either too low or too high).

    You could also take a look at the bq2427x family of parts that you can pair with a simple LDO at the output. Again you will be limited at the output if your only your battery is connected and the battery voltage dips below 3.3V + Vdropout(LDO). 

    Hope this helps,

    Regards,
    Joel H

  • 0 in reply to Joel Hernandez II
    Prodigy 240 points

    Hey Joel,

    Thanks a lot for your valuable suggestions.

    In fact my requirement is now a little changed, I now have two supply inputs for 5 V, one from USB and another from external 5 V.

    And I realise , as per your suggestion that putting an LDO will only worsen situation when the battery voltage dips below 3.3V +LDO drop.

    So I have come up with a solution as BQ2402x and followed by low cost buck boost to ensure a proper 3.3V.

    But I am quizzed with the various versions 'x' of BQ2402x, my requirement is simple and I may not use the other offered controls like CE, TS, PG, TTE.

    Do we have any other basic IC ? if not ,can you suggest which version I should go for ?

    Thanks

    Abhishek

  • 0 in reply to Abhishek Sharma53
    TI__Mastermind 25800 points

    Hey Abhishek,

    I think the bq2402x is a good part for your application. 

    As to which version, I would suggest a few depending on how your application is structured:

    1) If your product environment could have large temperature variations, I would recommend any of the parts that have the TS pin + a thermistor to monitor battery temperature. 020, 024, 025, and 026 all have this pin.

    2) If want to be able to deactivate the fast charge safety timer and charge continuously (usually in place to stop charging in the event of a fault battery), then you want either the the 024 or the 026 version. These have the /TE and /TTE pins. 

    3) If you want the simplest of the simplest with basic Charge On/Off control, then you're going to want the 022 or the 027. 

    Regards,

    Joel H