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BQ25180: bq25180

Joel Invers
Prodigy 70 points
Part Number: BQ25180
Other Parts Discussed in Thread: BQ25188, BQ25185

Tool/software:

Hello,

Considering the need to programm the bq25180 by I2C bus. I understand that any time the device is reset it must be programmed by the controller. Is this right? Or is this programming non-volatile?

In the case we hae the device only supplied by the batterty (Vin disconnected), may the device be programmed by I2C? Or do we always need Vin connectrd to acces the deice by I2C?

Thank you very much in advance.

Regards,

Joel

  • 0
    TI__Guru** 105600 points

    Hello Joel,

    That's correct, memory is volatile and will be lost anytime there is a POR or power is lost.

    You can communicate with the charger over I2C with only VBAT present.

    Sincerely,

    Wyatt Keller

  • 0 in reply to Wyatt Keller
    Prodigy 70 points

    Hello Wyatt,

    Thank you.

    The device I'm working on will usually be working using the battery. When the voltage of the battery would go down the programmed Vbuvlo value, the bq25180 should automatically disconnect the battery from the system. But it's not clear if the device goes to ship mode with a consumption of nA. What would be the consumption of the bq25180 from the battery in such condition?

    This a typical situation when the battery device would be a long time in the shelf and some chip manufacturers call it "shelf mode" for its chargers.

    Thank you very much in advance.


    Regards,
    Joel

  • 0 in reply to Joel Invers
    TI__Expert 8070 points

    Hello Joel,

    The BQ25180 disconnects the battery to protect it from deep discharge when the battery voltage drops below the BUVLO falling threshold. At this point, the device is effectively off.

    The BQ25180 supports two low-power modes:

    • Ship mode: This can be entered via I2C or by holding the push button for longer than the programmed tLPRESS duration (default 10 seconds). In ship mode, the device's quiescent current is 3.2uA (typical). Ship mode can be exited by holding the push button for the tSHIPWAKE duration or by connecting a valid input supply to VIN.
    • Shutdown mode: This can also be entered via I2C or a long button press if the push button is configured to enable shutdown mode. In shutdown mode, the device's quiescent current is 15nA (typical). The registers are reset in shutdown mode, and the only way to exit it is to connect a valid input supply to VIN.

    I'd also recommend checking out the BQ25188, which we recently released. It's the latest version of the BQ25180 and offers several features and improvements.

    Best regards,

    Alec Lehman

  • 0 in reply to Alec Lehman
    Prodigy 70 points

    Hello Alec,

    Related to the bq25180. When it disconnects in case of an Undervoltage in the battery, may you please confirm that it will recharge the battery when we will connect Vin power?

    Related to the bq25188. In the pdf published it's specified the values of VBUVLO to protect the battery from an undervoltage. But this function is not indicated in the first page of the pdf. I would suggest to include it like it's included in the pdf of the bq25180.

    I have to admit that I would be more confortable if the specs of the bq25180/25188 could be included in a standalone device or in a non-volatile configuration.

    Regards,

    Joel

  • 0 in reply to Joel Invers
    Prodigy 70 points

    By the way. May you confirm me that the bq25188 may suply peak currents up to 3Amps from the battery to the SYS output?

    Thank you very much in advance.

    Regards,

    Joel

  • 0 in reply to Joel Invers
    TI__Expert 8070 points

    Hello Joel,

    Joel Invers said:
    When it disconnects in case of an Undervoltage in the battery, may you please confirm that it will recharge the battery when we will connect Vin power?

    Yes, when the battery voltage is below the VBUVLO threshold but above the VBATSC threshold, the battery will charge at the precharge current. The precharge current can be programmed to be either 1x or 2x the termination current, which itself can be programmed to be a percentage of ICHG.

    Joel Invers said:
    Related to the bq25188. In the pdf published it's specified the values of VBUVLO to protect the battery from an undervoltage. But this function is not indicated in the first page of the pdf. I would suggest to include it like it's included in the pdf of the bq25180.

    That's a great point. I appreciate you bringing this up, and we'll consider it for future revisions of the datasheet. Thank you for your feedback!

    Joel Invers said:
    I have to admit that I would be more confortable if the specs of the bq25180/25188 could be included in a standalone device or in a non-volatile configuration.

    We have the BQ25185, which is the standalone (RC-settable) version of the BQ25180. Please feel free to reach out if you have any questions about it!

    BQ25185: https://www.ti.com/product/BQ25185

    Best regards,

    Alec Lehman

  • 0 in reply to Joel Invers
    TI__Expert 8070 points

    Hello Joel,

    Yes, the battery overcurrent protection (BATOCP) on the BQ25188 can be set up to 3A. This is an improvement over the BQ25180, which could only set BATOCP as high as 1.5A.

    Best regards,

    Alec Lehman

  • 0 in reply to Alec Lehman
    Prodigy 70 points

    Hi Alec,

    The bq25185 could be ok, except that it doesn't have the shutdown current of nanoampers that the bq25188 has. The bq25188 looks quite better in terms of shelf mode (when the device has to be stocked in a shelf during a long time).

    Thank you very much.

    Regards,

    Joel

  • 0 in reply to Joel Invers
    TI__Expert 8070 points

    Hello Joel,

    Both the BQ25185 and BQ25188 have the 3.2uA ship mode (called factory mode on the BQ25185). One key difference is that ship mode can be exited by a push button press, while the 15nA shutdown mode can only be exited by connecting an input power source to VIN. Additionally, the device registers are not reset when entering ship mode, but they are reset when entering shutdown mode.

    Please let me know if you have any questions about either device.

    Best regards,

    Alec Lehman

  • 0 in reply to Alec Lehman
    Prodigy 70 points

    Hello,

    I would need the 15nA shutdown mode.

    Regards,

    Joel

  • +1 in reply to Joel Invers
    TI__Expert 8070 points

    Hello Joel,

    Understood. Let me know if you have any other questions.

    Best regards,

    Alec Lehman