BQ25306: BQ25306 not charge at above 400mA with different RCHG Resister

VENKATESAN Balakrishnan

Part Number: BQ25306

Tool/software:

I am using bq25306 charging ic in my project for 8.4V battery and I try to charge my battery at above 1A.So, I changed the RCHG resister value 37.2K but my circuit produce at 400mA .

At 20k-400ma only produce

At 15k-400ma only produce

Changed different RCHG Resister but my circuit produce only 400mA

Vbus=12V -IBAT 280mA

Vbus =9V- IBAT 400mA

I am using 2.2uH inductor (SWPA5040S2R2NT)

Please help me my circuit did not charge 8.4V battery in above 400mA

I am trying different battery with diff PCB but problem not solved

2 months ago

0 Ning T 2 months ago

TI__Guru 57341 points

Hi,

When charging at 400mA, what are VBUS (voltage at VBUS pin), IVBUS, VBAT (voltage at BAT pin), IBAT, PMID (voltage at PMID pin), REGN (voltage at REGN pin)?

Thanks,

Ning.

0 VENKATESAN Balakrishnan 2 months ago in reply to Ning T

Prodigy 20 points

Thank you for your reply

Case 1:

Input voltage 12v from 3A DC power supply

Battery voltage:7.85V

Vbus: 11.65V

Ibus: 271mA

Vbat:7.91V

IBAT: 339mA

Voltage at PMID:11.46V

Voltage at REGN:5.010

Case 2:

Input voltage 9v from 3A DC power supply

Battery voltage:7.85V

Vbus: 8.83V

Ibus: 474mA

Vbat:7.91V

IBAT: 462mA

Voltage at PMID:8.69V

Voltage at REGN:5.011

0 VENKATESAN Balakrishnan 2 months ago in reply to VENKATESAN Balakrishnan

Prodigy 20 points

ICHG set resister:15k

0 Ning T 2 months ago in reply to VENKATESAN Balakrishnan

TI__Guru 57341 points

Hi,

1. Did you measure VBAT at the BQ25306 BAT pin?

2. Could you please also provide the BQ25306 FB pin voltage?

3. What's your target battery charge voltage?

Thanks,

Ning.

0 VENKATESAN Balakrishnan 2 months ago in reply to Ning T

Prodigy 20 points

1)yes we measure V bat at bat pin

2)fb pin voltage 1.030

3) target battery voltage 8.4v

Can you explain me on which scenario we will face low charge current problems.

0 Ning T 2 months ago in reply to VENKATESAN Balakrishnan

TI__Guru 57341 points

Hi,

Let us check and get back to you early next week.

Thanks,

Ning

0 Ning T 2 months ago in reply to Ning T

TI__Guru 57341 points

Hi,

Are you able to get 1A charge current when the FB pin voltage is lower (e.g. 0.88V)?

Thanks,

Ning

0 Ning T 2 months ago in reply to Ning T

TI__Guru 57341 points

Hi,

Are you able to get 1A charge current when the FB pin voltage is lower (e.g. 0.88V)?

Thanks,

Ning

Power management

Power management forum

BQ25306: BQ25306 not charge at above 400mA with different RCHG Resister