• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 64 subscribers
  • Views 740 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ27421-G1: Schematic review with gauge chip

agusta mir
Intellectual 480 points
Part Number: BQ27421-G1BQ24032A
Other Parts Discussed in Thread: TPD1E10B06

Hello,

I added a gauge chip to my existing design. Can someone help with a schematic review? I believe I have followed most instructions from the datasheet. Some of my specific questions are:

- Is GPOUT okay connected to PACK+, or should be connected to VDD pin(regulator output). I pulled down BIN through 10k since I don't need it.

- There is a 10uF cap(c28) across the pack terminals (from the BQ24032 design). Now that the gauge output is connected to the BAT terminal of BQ24032 chip, do I keep the cap?

- Can the CE chip on BQ24032 be pulled up with a 10k resistor or needs some other valued resistor (since PSEL has 100k pull-up).

- Can the LDO pin on BQ24032 be left unconnected. 

- I wanted to add TPD1E10B06 on the ACIN line. Should it be placed before or after the 10uF cap?

  • 0
    TI__Guru* 76230 points
    Hi Agusta
    No, the GPOUT pin absolutely has to be connected to a gpio pin of your host.
    The bin pin should be your thermistor of your battery pack. You are using a 10K resistor which is find if the battery thermistor is being used for the charger, but you have to configure the gauge to use the internal temp sensor or your host has to write the temperature to the gauge.

    pls post this on the charger forums so the charger portion of the schematic is reviewed as well.

    thanks
    Onyx
  • 0 in reply to Onyx Ahiakwo
    Intellectual 480 points

    Thanks for your comments, Onyx.
    I was referring Layout Guidelines section 11.1 of the datasheet. It suggests GPOUT can be pulled to VDD pin. I don't have a spare pin on the host for GPOUT - so I hope pulling to VDD will be okay?
    I am connecting the NTC to the charger, and will configure the internal temperature sensor. So I connected BIN through 10k to VSS. 

    How do I post to charger forum. I thought there is an integrated power management forum?

  • 0 in reply to agusta mir
    TI__Guru* 76230 points
    No it will not. The chip is susceptible to shut downs and connecting GPOUT to a gpio pin of your host is needed to wake the device up.
    When submitting the new post, put the charger no as the device.

    thanks
    Onyx