BQ24170: Charging Current Issue

Nishanth M

Part Number: BQ24170

I am facing problem in BQ24170 Charger IC following

1. If Input Voltage rises from 12V to 15Volt , the charging current also increases. Charging current not constant.

2. While charging the battery , if load is connected (2A) suddenly... the status LED starts blinking, but Battery is charging (charge Current decreased ,System Out Current Increased)

My Design Specs:-

1. Input Adopter 12.5V/5A.

2. Li-Ion 3.7 Volt/10A- Battery-3 in Series.

0878.Battery Charger.pdf

over 6 years ago

0 Ning T over 6 years ago

TI__Guru 52371 points

1. Please measure OVPSET voltage @ VIN=12V and VIN=15V respectively and check if the readings are normal.
2. Blinking STAT indicates fault. Please measure the input current when the load is connected (2A) suddenly and check if it is higher than the input current limit setting.

Thanks!

0 Nishanth M over 6 years ago in reply to Ning T

Intellectual 295 points

Thanks for your reply.
I have the voltages following are:-
1. Vin:- 12.37V
2. Vref:- 3.24V
3. OVPSET:- 1.13V
4. ACSET:- 0.58V
5. FB:- 3.24
6. ISET:- 0.39V
7. TS:- 1.85V
if I increase VIN to 15 Volt the charging current goes high more than 3A So the P-Mosfet will Fails.

Thanks

0 Ning T over 6 years ago in reply to Nishanth M

TI__Guru 52371 points

What are the voltages for these pins when VIN=15V? Thanks!

0 Nishanth M over 6 years ago in reply to Ning T

Intellectual 295 points

Thanks for all your support.

Problems Solved:-

1. QFN Mosfet Drain and Source is Reversed.

2. I changed the connections of Mosfet. Now Charging current is constant and also Status LED blinking solved.

Thanks

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BQ24170: Charging Current Issue