BQ51013B: Charging Issue

Sowmiya R

Part Number: BQ51013B
Other Parts Discussed in Thread: BQ51003

We have previously used BQ51003 supporting 500mA,but the IC didnt support 500mA in our board.So we bought BQ51013B with 1A .We did the below cases and found issues,
1.Tested for 200mA :
RILIM=1.1 K Ohm,worked as expected.
2.Tested for 500mA
RILIM=300 Ohm,but device was not continuosly charging and it stopped after few mins.
3.Tested for 800mA
RILIM=130 Ohm,device was not charging.
We want the IC to support all the above cases and we need the solution to solve this issue.

over 3 years ago

0 Bill Johns over 3 years ago

TI__Guru 65866 points

Hello

This could be caused by a couple of things.

The two devices are P2P compatible but RX coil and tuning may need to change. What coil are you using and what is the tuning?

Also the FOD setting may be an issue, what resistor are you using for R-FOD?

0 Sowmiya R over 3 years ago in reply to Bill Johns

Prodigy 40 points

Hi Bill Johns,
We are using our own customized 27uH inductance circular coil with 22mm diameter.
I have attached the circuit which we are using.Please suggest if there are any changes to be done.

0 Bill Johns over 3 years ago in reply to Sowmiya R

TI__Guru 65866 points

Hello

Sorry but did not see the attachment.

Can you give it another try?

0 Sowmiya R over 3 years ago in reply to Bill Johns

Prodigy 40 points

Please find the attachment

0 Bill Johns over 3 years ago in reply to Sowmiya R

TI__Guru 65866 points

Hello

Unit works at 200mA. 500mA stops after a few min, will not work at 800mA--couple of things to check:

1.) This could be thermal rise of the IC and tripping internal thermal limit, thermal pad needs good connection to thermal plane

2.) Not sure if R223 is NTC or only a resistor, if it is an NTC close to the device this could trip external thermal limit.

3.) FOD fault is more likely at higher current, increasing R225 to 250 to 300 will add margin. This value needs to be set on final design.

4.) R225 (Out to FOD) is not needed, R4 (RECT to FOD ) will meet FOD requirements.

What Coil are you using?

Also see FAQ listed below.

Startup Troubleshooting for Wireless Power RX: https ://e2e.ti.com/support/power-management/f/196/t/910420
How Do I Select Capacitor Values for a Wireless Power RX Coil?: https ://e2e.ti.com/support/power-management/f/196/t/905132
Why is Wireless Power RX Device Overheating? : https ://e2e.ti.com/support/power-management/f/196/t/905835
Schematic Checklist for Wireless Power RX: https://e2e.ti.com/support/power-management/f/196/p/925464/3419086
Coil frequently asked questions for wireless power RX: https://e2e.ti.com/support/power-management/f/196/t/942785

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BQ51013B: Charging Issue