BQ24616: Connection to have high current output

Giuseppe Leotta

Part Number: BQ24616

Dear Sir,
I need to connect this IC to a load that absorbs around 30A.
This is the schematic recommended on the datasheet:

I've the pover supply input in the ADAPTER side and the load in the SYSTEM side. If I use this scheme all the current (absorbed by the load and the current that chatge the battery) pass trought the resistor RAC and the device stop to charge the battery. I need that the device continueds to charge the battery also when the load is connected.

I would like to modify the schematic in this way:

in this way the RAC resistor is bypassed. Do you think it's the best solution to have what I need?

In this way I've a very high current inside the p-Mos Q1,Q2 and Q3. There is a way to bypass the transistors Q1 and Q2 with the current that from the adapter goes into the load?

Best Regards

Giuseppe

over 5 years ago

0 Kedar Manishankar over 5 years ago

TI__Mastermind 24075 points

Hi Giuseppe,

I see you are connecting a system load of 30A. Most likely your battery will not be able to support this. If you connect schematic how it is shown above, then if your adapter voltage decrease to hit SLEEP threshold, or if adapter is disconnected and drops below UVLO, the gate driver for Q1 and Q2 will turn off, and the gate driver for Q3 will turn on, allowing battery to supply system, and this will cause your battery to discharge immediately to support system load. Is such a scenario possible in your system, and if so have you verified that this discharge current is safe for your battery?

To disable input current DPM, you can replace RAC with a short, and tie ACSET to 3.3V.

0 Giuseppe Leotta over 5 years ago in reply to Kedar Manishankar

Prodigy 130 points

Dear Kedar,
thanks for reply. Yes, the battery is compliant with this function. I already test it. I already test also this configuration and it's seems work. I would like to know if this is a good solution or if you can suggest me a best solution to solve my problem.
Regards
Giuseppe

0 Kedar Manishankar over 5 years ago in reply to Giuseppe Leotta

TI__Mastermind 24075 points

Hi Giuseppe,

You can follow above instructions for disabling DPM, so that total input current is not regulated. Replace RAC with short, and tie ACSET to 3.3V. If input adapter is able to supply both load and charge current, then there will be no issue.

0 Giuseppe Leotta over 5 years ago in reply to Kedar Manishankar

Prodigy 130 points

Hi Kedar,

then ACP and ACN will be short circuit together, it's right?

Thank you for support.

Best Regards

Giuseppe

0 Kedar Manishankar over 5 years ago in reply to Giuseppe Leotta

TI__Mastermind 24075 points

Hi Giuseppe,

Yes that is correct.

Power management

Power management forum

BQ24616: Connection to have high current output