bq24266

Hirotsugu Kobayashi

Mastermind 9540 points

Other Parts Discussed in Thread: BQ24266

Hi, all

I have a question about bq24266

1. Is there an operational flow chart available?

2. In supplement mode, which is output of CHG?

3. Is a filter necessary to a TS terminal?

Best Regads,

Kobayashi

over 9 years ago

0 Jeff F over 9 years ago

TI__Guru**** 166996 points

Regarding 1, unfortunately no. The IC's asynchronous state machine is quite complex, with some portions being proprietary. Which operating mode/states are in question?
Regarding 2, /CHG should be high impedance when in supplement mode.
Regarding 3, no filter on TS is required.

0 Hirotsugu Kobayashi over 9 years ago in reply to Jeff F

Mastermind 9540 points

Hi, Jeff

When an ammeter is inserted between VBAT and the battery, a phenomenon of attachment occurs, and it can't charge.

I'd like to confirm which State it's by what kind of error.

When an ammeter is removed, the symptom doesn't occur.

When gauging with a current probe, such symptom doesn't occur.

Do you know what is the cause?

bq24266 DRV Oscillation.pptx

When having returned to a charge from a supplement mode, will CHG be Low again?

Ok, I understand.

Best regards,

Hirotsugu

0 Jeff F over 9 years ago in reply to Hirotsugu Kobayashi

TI__Guru**** 166996 points

Regarding 1, an ammeter in between the charger's BAT pin and battery adds quite a bit of resistance so constant voltage/taper time will be longer. Also, if the ammeter is set to auto range, it will likely oscillate. It is best to either using an oscope current probe to monitor battery current or for more accuracy, use a series resistor and voltage meters to measure the voltages across.

Regarding 2, I need to confirm this operation on the bench and get back to you.

0 Jeff F over 9 years ago in reply to Jeff F

TI__Guru**** 166996 points

Regarding 2, I was previously mistaken. /CHG indicator is not affected by supplement mode. As long as /CE is low and termination has not occurred, /CHG will be low for all new charge cycles but not refresh cycles (in other words, charge completes then battery discharges then charging restarts without adapter removal).

0 Hirotsugu Kobayashi over 9 years ago in reply to Jeff F

Mastermind 9540 points

Hi, Jeff
I grasp that method for measurement influences.
A DRV terminal becomes on, and oscillated one would like to know in what kind of state IC is.
I think the DRV terminal is always on when a power supply is supplied, but is it different?

0 Jeff F over 9 years ago in reply to Hirotsugu Kobayashi

TI__Guru**** 166996 points

DRV is only on when input power is applied.

0 Hirotsugu Kobayashi over 9 years ago in reply to Jeff F

Mastermind 9540 points

Then, why does DRV fall and oscillate, when an ammeter was connected.

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bq24266