bq2403x EVM questions

Q: bq2403x EVM questions

 Please help with the following questions,

1-       I understand that if the unit is powered with the DC Voltage Vac the D5 goes on and D4 is on when the battery is charged through USB.  What are  the D2 and D3 indicating?

2-       How long does it take a battery to be charged?

3-       I understand that USB high power it can be set in the control panel.  Does this mean that some computer can not provide the 500 mA through the USB?

4-       When do we know that the battery has been charged completely?

5-       Is ther certain battery that can not be used by this I.C?


A: Re: bq2403x EVM questions

1. D2 and D3 for STAT1 and STAT2, in datasheet page 24 has a table for status pins summary.

2. It depends on the battery capacity and charge rate.

3. USB spec need first in low power mode, after negotiation it allows draw 500mA.

4. Charger sensing charging current, at first it works in Constant current (CC) mode, when battery voltage reasches voltage set point, it enters into Constant voltage (CV) mode, current tapers down.

When charge current is small than termination current in CV mode, it is considered as charge done. Datasheet page 11 figure 1 gives the charging profile.

5. This IC has CC-CV charging profile, it is designed for single cell Li-Ion or Li-Pol battery.