BQ24103A

Keith Johnson2

Other Parts Discussed in Thread: BQ24103A, BQ24040

I'm using the BQ24103A in my design and when the battery pack drain to 2.5 V there is a circuit built in to the pack that lower the terminal voltage below 2.1V. The charger will not recharge the battery. I put my scope on the output of the charger and there were pulses but there is 1.57V on the other side of the the sense resistor. My goal is to keep the buck running so when a battery is below 2.1V (detect voltage) I can still charge the battery. Does anyone have a solution in order for me to achieve my goal?

over 9 years ago

0 Jing Zou over 9 years ago

TI__Mastermind 20570 points

Can you please share the scope capture on the issue along with the schematic? Please also share your battery pack protection schematic as well.

When the battery voltage is below 2.05V (VSHORT, short circuit voltage threshold), ISHORT is provided to charge the battery. Charge will be suspended if the battery voltage is not charged up to VLOW when the pre-charge timer expires.

0 Keith Johnson2 over 9 years ago in reply to Jing Zou

Prodigy 40 points

Hello Jing,'

Thanks for responding to my issue. My issue I believe is getting the battery detect pulses to work in our design. Attached is the waveform I captured from the EVM.

ThanksTI question BQ24103A.pptx

0 Keith Johnson2 over 9 years ago in reply to Jing Zou

Prodigy 40 points

Hello Jing,

Are you going to get back to me??? Also we are design for a charge current of 0.800A.

Keith

0 Jing Zou over 9 years ago in reply to Keith Johnson2

TI__Mastermind 20570 points

Sorry for missing this thread. I was trying to ask scope capture on the issue at your board not the EVM.

Have you tried to test with your battery at the EVM? Do you still observe the same issue? I don't see the voltage you described on your scope capture. Looks like the battery detection waveform is good.

Are you charging a single cell battery? if your charging current is only 0.8A, I would suggest you to use a linear charger. It is easier to design and saves you total bom cost. There is no need for the maxium output capacitance calculation for the battery detection circuit. I would suggest bq24040 for your application.

0 Keith Johnson2 over 9 years ago in reply to Jing Zou

Prodigy 40 points

Jing, Yes I have used the EVM to charge my battery and it works fine. Did you see anything in our design the appears to be a problem? I was also able to get the EVM to charge a deeply discharge battery, the pulse seem to slowly condition the battery enough to start charge algorithm. As for as changing to a different IC I'm not sure schedule will allow it. I will keep the linear in my back pocket.