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BQ24160A: system functions for dual supply

Bart
Expert 6360 points
Part Number: BQ24160A
Other Parts Discussed in Thread: BQ24160, BQ24133, TPS2121, TPS2120, TUSB320, BQ25601D, BQ25606, TUSB422, TUSB321, BQ25890

Team,

We are considering using one of the bq2416xx devices as those are dual input chargers with power path (that's what we need, the supplies are 5VDC and 5V USB).

 Can you help to understand if the below system functions can be met?

  1. When 5VDC is present, 5V USB is present, Battery is fully charged -> system runs from 5VDC
  2. When 5VDC is present, 5V USB is present, Battery is NOT fully charged -> the battery must recharge but the system runs from 5VDC  
  3. When 5VDC is NOT present, 5V USB is present, Battery is fully charged -> system runs from 5V USB
  4. When 5VDC is NOT present, 5V USB is present, Battery is NOT fully charged -> the battery must recharge but the system runs from 5V USB
  5. When 5VDC is NOT present, 5V USB is NOT present -> system runs from 3.5V to 3.7V Battery voltage.

Additionally, we are going to have USB type-C (only USB Type-C 5V 3A, not PD) - is that fine with bq2416xx?

Thanks for your help,
TI Customer

  • 0
    TI__Guru*** 148655 points

    Hi Bart,

    For any of our chargers with NVDC power path, the SYS output provides at least a minimum system voltage (3.6V typical) at the SYS output when there is power at the input. V(SYS) eventually rises to V(BAT) as the battery charges. For the BQ24160 with dual input, the charger I2C register has a bit that allows you to select input precedence if both are connected. It will choose whichever one is present to charge.

    So the answer to 1 to 4, is yes, except we do not pass through the 5V but provide a bucked down version no lower than ~3.6V typical.

    When no power is applied, the V(SYS) = V(BAT) - ISYS*Rdson until the battery voltage drops to VBATUVLO, which is the 2.xV range.

    So, the answer to 5 is yes except the battery continues to discharge below 3.5V.

    Regarding type C, the charger cannot communicate with type C and so additional hardware and/or software will be necessary to increase USB type C output current from default 1.5A to 3.0A.

    TI has other single input chargers that provide a pass through path from the 5V input to the system output (BQ24133 for example) if that is a hard requirement.

    Can you provide the battery capacity and end application?

  • 0 in reply to Jeff F
    Genius 4650 points
    Hi Jeff,

    1) the battery can be one to four parallel connected 18650 Li-ion battery cells (cca 2500-3000mAh per cell).

    2)IF we use BQ24160 with USB C connector and don't have the logic to communicate, will then the charge current be always 1.5A?

    3) what hardware/software have you in mind to do the logic for type-C?

    4)We would like to use USB Type-C , can you suggest a USB Type-C charger?

    5) Do you have a USB Type-C charger with dual power path ( USB and AUX DC)?

    6)IF no on question 5) -> What do you think about to use a power mux eg. TPS2120 or TPS2121 before a USB type-C charger?

    7) Can the power mux decide if the USB voltage and AUX DC voltage is connected to choose AUX DC voltage?


    Best Regards,
    David.
  • 0 in reply to d_zero
    TI__Guru*** 148655 points
    David,

    Regarding 1, if 4 parallel batteries and no access to I2C to change the charge safety timer, I worry that the timer will expire before the battery is charged.

    Regarding 2, the default input current limit on USB input is set by the D+/D- pins. If an SDP source is detect, the input current limit is 100mA, otherwise it is 1.5A (meaning charger current will not much higher than 100mA or 1.5A from a 5V source). The default battery regulation voltage is only 3.6V not 4.2V so you will need I2C to change the regulation voltage to 4.2V and therefore fully charge.

    Regarding 3, we have been recommending either TUSB320 or TUSB420 family plus software to interface with usb type C source in front of the charger. Unfortunately, I do not support those USB communication devices.

    Regarding 4,5,6, TI currently does not have a standalone type C charger. BQ24160 is the only dual input charger that we have. For dual input, we have been recommending TPS2121 plus BQ25601D 3-A charger family.

    Regarding 7, the developer can program the mux's input source priority with auto switchover if the priority source is no longer available.

    So in summary, I recommend BQ25601D or BQ25606 + TUSB320 or TUS422 + TPS2121.

    Regards,
    Jeff
  • 0 in reply to Jeff F
    Genius 4650 points
    HI Jeff,

    1)
    I don't understand why you suggest a PD device TUSB422?

    We have USB 3 Gen1 speed, and we would like to have Type C connector and "USB Type-c" specification ( 5V 3A), we don't need the PD specification (20V 5A) .

    2)
    If we for the type c logic use the following CC controller TUSB321 and for the mux switch HD3SS3202RSVT.

    And as we have USB 5V voltage and a aux 5V DC voltage. We can use the TPS2121 for the power mux and can limit the current to 3A because of the "USB Type-C" specification.

    Now the output from TPS2121 5V,3A is applied to the battery charger input:

    a) Which battery charger do you suggest that can handle 3A input current ( BQ25601D or BQ25606 or any other) ?

    b) what is then the output voltage and current from the battery charger ? I mean what is the voltage for the LOAD (our system).

    c)you mentioned when we have more the one battery cell in parallel then we need to adjust the charge safety timer.
    How can we do that? -> So in order to do that we need a battery charger that has I2C

    3)
    "The default battery regulation voltage is only 3.6V not 4.2V so you will need I2C to change the regulation voltage to 4.2V and therefore fully charge."

    I don't understand this statement?

    Best Regards,
    David.
  • 0 in reply to d_zero
    TI__Guru*** 148655 points
    Hi David,

    Regarding 1, I am not familiar with the TUSB products and so recommended TUSB422 by mistake.

    Regarding 2a, the BQ25601D requires a host to communicate with it via I2C. The BQ25606 is standalone, not requiring I2C host. Both have D+/D- input pins that perform primary detection and secondary detection of the USB input source's current capability and set the charger's input current limit no higher than that value. For example, a legacy PC USB port would be detected as an SDP and the input current limit set to 500mA. The developer can use I2C to change the input current limit via I2C.

    Regarding 2b, both BQ256XX chargers have 3.25A maximum output current. For higher output current, I recommend the BQ25890. All of these chargers have default battery regulation voltage of 4.2V and provide a minimum system voltage of 3.7V at the SYS output when the battery is discharged below that voltage. When a power source is applied to VBUS, V(SYS) 3.7V then 50mV + V(BAT) as the battery charges to 4.2V.

    Regarding 2c, yes, you can only change the safety timer of the devices mentioned above via I2C. The BQ25606 has a 10 hour fixed safety timer.

    Regarding 3, as a precaution, the BQ24160 default maximum battery charge voltage is 3.6V not 4.2V. To fully charge a LiIon battery, the host software must write 4.2V to the charger's battery regulation voltage I2C register.

    Regards,
    Jeff
  • 0 in reply to Jeff F
    Genius 4650 points
    Hi Jeff,

    A)What is the Vsys when the battery is fully charged ?

    Our input power from USB is 15W (5V * 3A) , and from DC AUX is also 15W because the power mux a current limit on 3A.

    B)then the max output power when the battery is discharged from BQ25601D or BQ25606 to load is Vsys * Iout = 3.7V * 3.25A = 12W ?

    C)and the max output power from BQ25890 is 3.7V * 5A = 18W -> because of input limit the output will be 3.7V * 4A =15W ?

    D) when there is no battery, and the system runs from USB or AUX power only , what is the value of the Vsys?

    Best Regards,
    David.
  • 0 in reply to d_zero
    TI__Guru*** 148655 points
    Hi David,

    Regarding A, V(SYS) = V(BAT)=50mV so 4.25V.

    Regarding B and C, for the both charger families, the maximum recommend discharge current from BAT to SYS (when VBUS is either not applied or the charger is in full supplement mode) through the internal battery FET is 6.0A so approximately 6.0A*3.7V.

    Regarding B and C, with VBUS applied, the buck converter for the BQ256XX family can provide up to 3.25A to SYS, split between system load and battery charging current while the BQ2589X family can provide up to 5A.

    Regarding D, when no voltage is VBUS is applied, V(SYS) = V(BAT)-ISYS*RdsonQ4 where Q4 is the internal battery FET.

    Regards,
    Jeff
  • 0 in reply to Jeff F
    Genius 4650 points
    Hi Jeff,

    what about when VBUS available but there is no battery (battery is not connected) -> then the VSYS is also 4.2V ? And the max current for BQ256XX is 3.25A

    Best Regards,
    David.
  • 0 in reply to d_zero
    TI__Guru*** 148655 points
    David,

    With no battery attached and charge disabled, the regulation voltage is the MINSYS voltage of 3.7V.

    Regards,
    Jeff
  • 0 in reply to Jeff F
    Genius 4650 points
    Hi Jeff,

    thank you for the support, as we changed the IC i open a new question in following topic:
    e2e.ti.com/.../779792

    Best Regards,
    David.