Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 963 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.

BQ24167 CV mode terminate charger when charger current below Iterm

Chia Hung Lin
Prodigy 160 points
Other Parts Discussed in Thread: BQ24167, BQ24165

The page 15 of BQ24167 spec lists a sentence as below. I would like to know if it means that the bq 24167 will turn off charger in CV mode when charging current is below Iterm? Our DUT is working in USB 500mA charging. I find that when the Battery gauge reaches to about 90% SoC, the charging current will drop from abuot 190mA to 0mA which the charger stop charging and just supply current to DUT only. I think maybe the DUT sometime sinks to many currents and then charging current suddently drops below Iterm so the charger stop charging. But why DPPM doesn't work in this moment?

"The bq24165/6/7 monitors the charging current during the voltage regulation phase. If the battery voltage is
above the recharge threshold and the charge current has naturally tapered down to and remains below
termination threshold, ITERM, without disturbance from events like supplement mode for 32ms, the bq24165/6/7
terminates charge and turns off the battery charging FET."

  • 0
    TI__Guru**** 152756 points
    The charge current must remain below the termination current for 32ms for termination in CV to occur. If the SYS output demands more current than the IC can supply, the IC goes into supplement mode (DPPM) and the 32ms timer starts again.
  • 0 in reply to Jeff F
    Prodigy 160 points

    Let me describe the problem. The DUT(cell phone) is charged from PC USB port(500mA) and when the battery capacity reaches to around 90%. The charging current flowes into battery will drop from about 200mA to 0mA which means DUT stop charging. Is it because the charge IC goes into termination in CV as you mentioned in the frist sentence? But you also mentioned the charge IC will goes into DPPM in second sentence? Which one is true and why the DUT stop charging? 

  • 0 in reply to Chia Hung Lin
    TI__Guru**** 152756 points
    What is the voltage between the charger's BAT and GND pins? What is the impedance from the BAT pin to the battery. If high impedance and V(BAT) =VBATREG, then the charger has terminated. Since the charger current is so low, it is unlikely that DPM is involved.
  • 0 in reply to Jeff F
    Prodigy 160 points

    The voltage between the charger's BAT and GND pins is 4.08V. We put a PMOS between Charger IC BAT pin and Battery, the Rds on is 48mohm(typ).

    I'm sorry that I would like to provide a battery gauge log file to explain the exact status that we are are working on. Please refer to the attach log file for the charging status of battery gauge on voltage/current/percentage. The main steps are listed as below.

    1. System consumes around 250mA at 77%

    2. Connect to PC USB(500mA) and the charging current on battery is around 2xxmA

    3. It shows "Charger Status = Off" at 88% that means the CHG pin is in high impedance mode, but charger IC is still charging(recharge mode?)

    4. The current is 0mA at 92%.

    My question is why the chrager IC stop charging in 92%?0816_77%_PC USB charges to 92% only.txt

  • 0 in reply to Chia Hung Lin
    TI__Guru**** 152756 points
    For a new charge cycle, the charger stops charging when V(BAT) > VBATREG = 4.16V-4.24V ( or 4.02V-4.1V for TS indicating JEITA WARM) and ICHRG < ITERM = 10% ICHRG setting per ISET pin for 32ms. What is the voltage on TS? What is ICHRG per ISET pin?