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BOOSTXL-BATPAKMKII: What is the current consumption of the board?

Part Number: BOOSTXL-BATPAKMKII
Other Parts Discussed in Thread: BQ24250, BQ27441-G1

Hi,

I would like to know the current consumption of the board in normal mode, sleep mode, hibernate mode and shutdown mode of BQ27441.

The BQ24250 is in HZ mode.

When I am in normal mode of the BQ27441, I measure 15mA for the board.

When I am in shutdown mode of the BQ27441, I measure less than 0.5 mA for the board.

So I concluded that it was the BQ27441 that consumed a big part of the current.

But on the BQ27441-G1 datasheet the current are very low (section 8.5).

Also I would like to go in sleep mode and hibernate mode.

I have try two methods to go in sleep mode but no one of them work so I cannot access to the hibernate mode.

method 1:

I tried to change the value of SleepCurrent(subclass ID 82 offset 31) but the value I read is 172(0x00AC) and normaly need to be 10(0x000A) on default. I tried to change this value but it's not working.

I can read correctly and modify the values before(Taper Rate and Taper Voltage) and after(Voltage at Charge Termination).

To read and modify I use the method in section 3.1 of the bq27441-G1 technical reference.

method 2:

I tried to force the SDA to 0(GND) and in other time SCL to 0(not in the same time). But the consumption was around 15 mA for the board and I can verify if I was really in the sleep mode.

See section 9.5.4.9 in the datasheet.

I have two boards and the result are similar.

Best Regards,

Pierre Krebs

  • Pierre,

    I saw your post asking for help on the other thread, I'm more on the MCU side of things but I can definitely help you or at least find someone who can help.  I've got a couple of other things pressing me right now, but I'll look into this for you soon.

  • I would like to offer some comments.

    Where exactly is the current being measured?
    The BoosterPack has many IC's on the board.
    Two buck boost regulators for 3.3 and 5V, a charger and a connector up to the LaunchPad board.
    Schematic page 19 of www.ti.com/.../slau618.pdf,

    Sleep current of bq27441 is very hard to measure, it is dependent on if there is I2C traffic.

    0.5mA with bq27441 in shutdown is all BoosterPack.
    bq27441 shutdown is 600nA, 3 orders of magnitude lower than 0.5mA

    bq27441 normal mode current is 93uA, nowhere close to 15mA.
    That is all boosterpack current.

    Section 8.5 of bq27441-G1 data sheet are true values.
    All given with the Wake comparator disabled.
    These values are by design and can be trusted.

  • Hi,

    The current that I measure is 15mA when the module is connected with nothing.

    It's also the value return by the module when I read the current value in the BQ27441 with the I2C bus.

    The measure is make on one of the wire of the battery.

    Best Regards,

    Pierre Krebs

  • That's good Pierre,

    The BoosterPack is running off the battery.
    The gauge is measuring the current being pulled from the battery and puts it in the register.

    So your results agree with each other.

    It is working correctly.

  • Than you Ed,


    What I don’t understand is where this current is going. As you mentioned in your previous message, quiescent current of each circuit is far below this 15mA so I can’t find what is consuming this 15mA when the booster is not connected to anything.

    Best Regards,
    Pierre Krebs
  • In the BoosterPack user guide, the schematic shows 2 TPS6300x buck boost converters making +5 and +3.3V.

    These voltages go to the Launchpad connector.

    The TPS6300x  have their PS PowerSave mode disabled, by pulling the PS/SYNC pin high.

    Their datasheet shows the Iq being in the 50uA range, so that by itself should not be causing the current.

    However the voltages created go to the connector, so I must surmise that something is installed in that connector that is drawing the current.

    Do you have the MSP430 Launchpad connected?

    If so then that is what is consuming that current.

  • I did the measurement without connecting anything and with the Launchpad MSP432.
    In the both cases the current is around 15mA.

    Best Regards,
    Pierre Krebs
  • Where exactly are you measuring current?
    Can you send a picture?

    And do you have the USB cable connected?
  • Hi,

    when the value is 00.00012 the switch is on ''disconnect''.

    When the value is 00.01344 the switch is on ''connect''.

    The value is in Ampere.

    The black device convert 1mA to 1mV

    Best regards,

    Pierre Krebs

  • When the switch is "disconnect" the battery is not attached to the board.
    The current should read zero.
    So the calibration is off a little.

    It would be helpful to scope the current.
    A DVM will try to average the readings. The I-V converter may do the same.
    Whenever a question arises about current, the most accurate way to see it is with a scope.

    Battery current will very likely not be dc, rather it is pulsed in normal applications.
    Pulsed current would not be seen correctly by the DVM.
    And if it is pulsing, the nature and timing of the pulses may help lead us to the cause.

    I suggest experimenting with the setup.
    If there is really 15mA average being pulled then the battery gauge will show a capacity drop.
    The Tool is really made to demonstrate programming and communication using a MSP430.

    For in depth development we recommend the EVM, EValuation Module.
    Gauges need to be calibrated as well, and I don't know if the BoosterPack Tool was calibrated before sending out.
    In the bq27441 EVM, sluuap4a, there is a calibration section.
    Virtually all gauges they must be calibrated.
    www.ti.com/.../toolssoftware
  • Hi Pierre 

    Was you able to reduce the current consumption of the batpak?

    I am using the same unit and am having the same problem with my application consuming approximately 2mA but the batpak circuit is consuming 7x the current and completely draining the battery.

    Regards

    Gurvinder

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