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Need Power Path IC for battery system

skanuri
Prodigy 70 points
Other Parts Discussed in Thread: TPS63030, BQ25040, BQ24040, BQ24030, BQ24070, TPS63000, TLV3012, TPS63020

Hi,

       I am designing a circuit to increase the usability of a single cell lithium battery by using TPS63030 buck-boost converter to give adjustable output. Since this will be packaged with the battery, I need to design a way to charge the cell inside the target device with only two power wires. Is there any single IC solution for this? If not can you point me to other TI devices which can help me to achieve this?

Thanks

 

  • 0
    TI__Guru**** 151290 points

    Are you looking for a single cell battery charger?  We have several to pick from, including the bq25040, bq24040, bq24030.  All of those are linear chargers.  The bq24150 is a switchmode charger.

  • 0 in reply to Chris Glaser
    Prodigy 70 points

    Thank you for your reply. I am using the charger from the target device.  TPS63030 is configured to give regulated voltage of 3.3V  from the battery which can be from 2.7V to 4.1V. Battery along with TPS63030 circuit is connected to the target device using possitive and negative wires. I need suggestion for power path management to charge the battery from the device.

    Thanks

  • 0 in reply to skanuri
    TI__Guru**** 151290 points

    The bq24030 or bq24070 have a power path to charge a battery and power the system.

  • 0 in reply to Chris Glaser
    Prodigy 70 points

    Hi,

           I am giving more clarification about my requirement.  I package my DC-DC converter circuit along with battery protection and whole thing will look like a standard battery with two terminals (+ and -) to the charger except the battery output is 3.3 V from TPS63030. We need to connect this to the device battery terminals. The charger circuit is already present in the target device. This means , we need some way of providing charging path to the battery behind the TPS63030. Can you suggest any device which can help in implementing this.

     

    Thanks

  • 0 in reply to skanuri
    TI__Guru**** 151290 points

    If the output of your battery pack is the 3.3V output of our regulator, you cannot use that same connection to charge your battery.  The TPS63030 converts power in one direction--from your battery to the 3.3V.  It is not designed to convert power from its output to its input.

    If a DC/DC converter is in your battery pack, you will need a separate connection to the battery to charge it.  Maybe install a switch in your pack that switches the connection on the 2 wires from the output of the TPS63030 to the input to the battery for charging purposes.  Or you could have a comparator inside of the pack that looks at the voltage on the two wires.  If it is 0V, it enables the TPS63030 and activates a switch to connect the TPS63030 output to the wires.  If it is 5V, then it disables the TPS63030 and connects the wires to the battery to charge them.

    The bq24150 supports USB OTG (on the go).  It is designed to charge a battery and also transfer that battery power to a 5V bus for USB.  This could be your solution if a 5V pack is acceptable.  Is that the type of functionality you are looking for?

  • 0 in reply to Chris Glaser
    Prodigy 70 points

    Thanks for your reply and suggestions. bq24150 is a good part for the 5V but unfortunately I can not use 5V for the pack. I am exploring your suggestion to use comparator and switch.

  • 0 in reply to skanuri
    TI__Guru**** 151290 points

    You could always use the bq24150 in your pack and have the TPS63030 externally, if you wanted.  Possibly the TPS63030 could be in a separate attachment that plugs into the pack when you want to use the pack as a source and unplugs when you want to charge the pack.

    The thing that you need to figure out, based on what your final system requirements allow, is how to switch between charging and discharging.  Is a manual switch ok or do you have to have some automatic detection algorithm.  If the pack is in discharge mode (TPS63030 connected to the output and switching), then you can't just put a charger on the output immediately.  You need to signal the switch somehow to get it to change the connection to the pack instead of the output of the switcher.

  • 0 in reply to Chris Glaser
    Prodigy 70 points

    Thanks for your advice. Since the automatic detection and switching is rather complicated, I am implementing the system using manual switch over. I am using TLV3012 for battery protection and TPS63000 for DC-DC converter. However I have found another device TPS63020 which has some more additional features at higher price. Can you advice me on the main advantages of TPS63020 over TPS63000 for this application which may justify the higher cost ?

  • 0 in reply to skanuri
    TI__Guru**** 151290 points

    The TPS63020 is a brand new buck boost converter.  It's main advantage is 4A switches that allow very high output currents.  The TPS63000 has 1.8A switches, and can deliver roughly half of the output current that the TPS63020 can.  This is the main difference between the devices and the main item that drives the cost up.  As a newer part, the TPS63020 also has some additional features, such as a PG output, that the TPS63000 does not.  The TPS63020 also has a higher switching frequency, resulting in reduced inductor size/value.