BQ24003: Operation at Power On with no battery or pre-charge battery connection condition

Hi Kohei,

BQ24003 is an older part so information is very limited beyond what is in the d/s. If you are willing to switch, the BQ24040 is a newer part that provides info on the battery detect routine (section 8.4.12 of d/s). 

Best,

Nick-san,

Thank you for your reply.
Now I'm asked from our customer who are using bq24003 about bq24003 power-on timing operation. So we aren't willing to switch part.

I would like to know about bq24003 power-on timing operation not described in the datasheet if you have any information.

Could you give me information as there is battery detect function or not etc...?

Best Regards,
Kohei Sasaki

Kohei,

Is the customer encountering problems and looking for additional info to fix or understand the problem?

If so, could you describe what problems they have encountered?

Information on this device is limited to what is available in the data sheet.  But this is an older device, released in 2000 and is different from later Li-Ion chargers.

Start up of the BQ24003 has precharge, constant current and constant voltage then termination. 

Precharge current is limited to 60mA and is based on battery voltage 0V to 2.9V. 

Constant Current phase is from 2.9V to 4.2V and the current is set by current sense resistor. 

Constant voltage phase starts at 4.2V where the voltage will not increase and current will decrease as battery completes charge. 

Termination has two possible conditions, Max Charge Time set by TMR SEL or Min Current.  The Min Current, during voltage taper, decreases to about 20% of Constant Current.  At this point a 22 minute timer starts and Charge is Terminated when the timer expires.  A separate Charge Timer can be set to 3hr, 4.5hr or 6hr.

The termination condition are different from what is used in current devices. The BQ2404X family is different in:

1.)    Low battery voltage, less than 0.8V is short circuit condition and current is lower than precharge.

2.)    Precharge to Fast Charge transition point is moved lower to 2.5V

3.)    Termination is based on current, typically 10% of fast charge only. No 22 min timer.

Best,

Nick-san,

Thank you for your support.
After that, we confirmed customer's problem is caused by their external circuit.

I have another question about POR delay.

POR delay is 1.2ms to 3ms in the datasheet.

Is this delay the time that device starts operation after Vcc voltage is over start threshold?

For example, Does charge current start flowing after POR delay time after Vcc is added?

Best Regards,
Kohei Sasaki