BQ25616: Could you review schematic for BQ25616?

Downey Kim

Expert 2675 points

Part Number: BQ25616
Other Parts Discussed in Thread: BQ25606,

Hi TI expert,

The battery charging current max is only 500mA. charging current set is 2.62A(677/258).

Input current set is 2.39A(478/200).

Vin = 12V

Please check if there are any mistakes in the circuit.

Thanks,

Downey Kim.

over 4 years ago

0 Ricardo over 4 years ago

TI__Genius 10385 points

Kim,

I have one concern if TS is to be used. R13 should be 5.3kohm and R14 should be 31.14kohm.

Best Regards,

Ricardo

0 Downey Kim over 4 years ago in reply to Ricardo

Expert 2675 points

Hi Ricardo,

TS pin is not used. Are there no problems other than TS pin?

Thanks!

Downey Kim.

0 Ricardo over 4 years ago in reply to Downey Kim

TI__Genius 10385 points

Kim,

No problem then. I saw J3 and assumed it was being used, but you have clarified this is not the case.

Best Regards,

Ricardo

0 Downey Kim over 4 years ago in reply to Ricardo

Expert 2675 points

Hi Ricardo,

Thanks for your support.

I am testing after designing the PCB, but there are some problems.

1. Changing the resistance values connected to the ILIM and ICHG pins does not change the fast charge current.

Max charging current : 1.5A. (It does not change above or below 1.5A.)

If the system load is increased(over 2A), the charger output is decreased. and Battery discharge increases.

2. When the battery is charging (charging current 1.5A), the REGN voltage drops to 3.7V. (Charger input voltage : 12V)

As described above, the charger does not operate normally.

Please give me some advice.

Thanks,

Downey Kim.

0 Ning T over 4 years ago in reply to Downey Kim

TI__Guru 57651 points

Downey,

1. Please refer to 9.3.6.2 Dynamic Power Management.

2. Please visit https://e2e.ti.com/support/power-management/f/196/t/890626 for BQ25606: Schematic Review and PCB Layout Design Tips.

Additional Information including FAQs is available http://www.ti.com/lit/an/slva924/slva924.pdf Designing A Standalone Single Cell 3-A Charger with the bq25606. BQ25616 is similar to BQ25606.

Please check if STAT pin indicate any faults and debug from there. STAT pin blinks 1Hz when Charge suspend (input overvoltage, TS fault, timer fault or system overvoltage or battery overvoltage).

Thanks,

Ning.

0 Downey Kim over 4 years ago in reply to Ning T

Expert 2675 points

Hi Ning,

Thanks for the advice.

We solved it by changing 2 points of the capacitor.

1. BTST cap : 47nF -> 470pF. Is it okay to change the BTST cap?

2. VBUS cap : 1uF -> 4.7uF(Electrolytic capacitor)

If ceramic capacitor 4.7uF is applied, BQ25616 had abnormal operation. Why doesn't it work with ceramic capacitors?

Could you explain the above phenomenon?

Thanks,

Downey Kim.

0 Ricardo over 4 years ago in reply to Downey Kim

TI__Genius 10385 points

Downey,

I do not suggest changing the BTST cap value. Are you able to recreate this abnormal behavior on the EVM?

Best Regards,

Ricardo

Power management

Power management forum

BQ25616: Could you review schematic for BQ25616?